The factors affecting the resistance of a metalic conductor Essay Example for Free

The factors affecting the resistance of a metalic conductor Essay I1 12 As I have found from my experiments, the results I obtained show that the factors I predicted of affecting the resistance of a wire have proved true. Firstly, the factor of length increasing and resulting in an increase of resistance of the wire held true, because, as I varied the lengths of the wire form 50cm to 200cm the resistance increased from approximately 5 to 20. Secondly, the factor of the cross sectional area increasing and resulting in a decrease of the resistance of the wire also held true, because as I varied the cross sectional areas of the wire from 0. 4mm to 0. 91 mm, the resistance went from approximately 5. 4 to 0. 9. The above-mentioned results occur due to the fact of how many free electrons are being conducted through the wires of different lengths and areas.   In the case of length; the resistance increases as the length increases because a wire with a shorter distance will have a smaller amount of atoms for the free electrons to hit. Whereas a wire with a longer distance will have more atoms for the electrons to hit and the resistance gradually increases as a result.   In the case of the cross-sectional area; a wire with a greater area allows more electrons to flow through it as well as having more channels for the electrons to flow through it. As a result the resistance decreases, because current can flow without any restrictions. Whereas a wire with a smaller area all a smaller number of electrons to flow through it resulting in diminished flow of current through the wire. Thus the resistance increases because the current is flowing with restrictions. From the graphs on the following pages, I have illustrated my results obtained from my experiments and done so with the relationship between the current [I] and the voltage [V]. As predicted earlier, the graphs explain how, as the length of the wire increases, the resistance also increases, as shown in the graph I. As well as explaining how, as the cross sectional area of the wire increases, the resistance decreases, as seen in graph II. I have also plotted a graph to the effect on the resistance of the wire when a specific type of circuit is being used. A series circuit effect is seen in graph III and a parallel circuit effect is seen in graph IV. GRAPH I:   Length as a factor affecting the resistance of a wire: From the graph, we can see that the shorter the wire, the steeper the slope. Each line represents the wires I used that were of lengths ranging from 50cm to 200cm. The 50cm wire line has the steepest slope, thus we say it has the lowest resistance, while the 200cm wire has the least steep slope and we say it has the highest resistance. However to verify this fact I calculated R from the graph and found: For the length of the wire: 50 cm GradientÃ'Ž Therefore; R =1/0. 05 = 20 Below is my observation table that compares the value of R from my tabular calculations and the value of R from my graphical results: Length [cm] Calculated value of R [] Graphical value of R [] R/L [] 50 5. 06 5 100 9. 83 10 150 14. 63 13 200 19. 87 20 This graph shows, that the length of the wire is directly proportional to the resistance. GRAPH II: * Cross sectional area as a factor affecting resistance of a wire: From the graph, we can see that the thicker the wire the steeper the slope. Each slope represents the various thickness of wires I used ranging from 0.4mm to 0. 91mm. The 0. 4mm wire has the least steep slope, and we say that it has highest resistance, whereas the 0. 91mm wire line has the steepest slope and thus we say it has the lowest resistance. However I must verify these facts form my graph and calculate the value of R from the graph. Therefore; R = 1/0. 54 = 1. 8 0. 91mm Gradient = 1. 03 0. 81/ 1. 0 0. 8 = 0. 22/0. 2 = 1. 1 Therefore; R = 1/1. 1 = 0. 9 Below is my observation table that compares the value of R from my tabular calculations and the value of R from my graphical results: Area [m ] Calculated value of R [] Graphical value of R [] R x A [] 0. 12 5. 49 4. 8 0. 25 2. 86 3 0. 39 1. 62 1. 8 0. 65 0. 97 0. 9 This graph shows that the cross sectional area of the wire is inversely proportional to the resistance of the wire. GRAPH III: * A series circuit as a factor affecting the resistance of a wire: From the graph, we can see that when we use a wire of length 50cm, and pass current through it, via a series circuit the resistance is slightly less, than when we pass current through two wires of lengths 20cm and 30 cm and connect them with a series connection then the resistance is slightly higher. This is because were doubling the length of the resistor, thus we say that the resistance increases with the total length of the resistors. To verify my findings   Below is my observation table that compares the value of R from my tabular calculations and the value of R from my graphical results: Length [cm] Calculated value of R [] Graphical value of R [] 2030 6. 04 6. 8 50 5. 06 6. 2 GRAPH IV:   A parallel circuit as a factor affecting the resistance of a wire: From the graph, we can see that when we use a wire with a smaller cross sectional area and pass current through it via a parallel circuit, the resistance is slightly higher than when using a normal circuit. This is because placing resistors in parallel is equivalent to increasing the cross-sectional area A through which current can flow. In my graph I have used a wire of thickness 0. 4mm and passed current through it using a parallel circuit, and the resistance is lower. The resistance for the 0. 56mm wire when passing current through it using a normal circuit is higher. However to verify my findings, I calculated the value of R from my graph and found: 0. 4mm Gradient =Therefore; 35 Therefore; R =1/0. 35 = 2. 8 Below is my observation table that compares the value of R from my tabular calculations and the value of R from my graphical results: Area [m ] Calculated value of R [] Graphical value of R [] 0. 12 2. 62 3. 33 0. 25 2. 86 2. 8 MATHEMATICAL DEDUCTIONS TO FURTHER PROVE MY RESULTS: Consider a wire of length l Where; A = cross -sectional area / number density of electrons n = electron density =number of free electrons per unit volume If voltage V, is applied to the wire, the electrons will drift to the positive terminal with a velocity, v. Volume of the wire = AlÃ'Ž Number of free electrons in conductor = n x A x l = nAl Total charge that is free to move = n x A x l x e =nAle Current = charge/time = Q/t Time required for all electrons to emerge out of the end of the conductor = l/v Therefore; I = Q/t = nAle/l/v = nAve Drift velocity (from battery cell) is the EMF, Therefore; Force = mass x acceleration (force to move current) Acceleration = velocity/time L = m x v / t Work is done by voltage in moving electrons i. e. acceleration: Work done = Force x Distance Distance = l Therefore; work done/electronic charge = w/e Work done per unit charge = V = w/e = lÃ'Ž Therefore; V = l x m x v/et R = V/I therefore; V = l x m x v/et = l x m x et I = nAve nAe From my analysis I can conclude that as the length of a wire increases, so does the resistance. This is because there is a larger amount of wire to travel up and therefore there will be more factors to increase resistance I can now sat that I believe my experiments were quite accurate as I performed them fairly and properly, this is demonstrated in the good results I have obtained. My measurements were accurate enough as I used digital ammeters and voltmeters, making them more reliable. In doing so I also avoided the possibility of parallax errors as well as zero errors. Were my results accurate to draw a conclusion? I was able to draw a valid conclusion for the measurements of current and voltage, as they were more or less what I expected to attain. I managed to prove that resistance is proportional to length as length increases, the resistance of the wire increases and that resistance is inversely proportional to the cross sectional area as cross sectional area increases, the resistance of the wire decreases. As well as that, for 2 wires connected via a series circuit combination, the resistance pattern will be the same as that when length of a wire is varied. Whereas for 2 wires connected via a parallel circuit combination, the resistance pattern will be the same as that for when area of the wire is varied. My results did not agree fully with my heat theory as they showed slight variations, such as a 14. 63 result instead of a result close to 13 for a wire of length 150cm. And a 19. 87 result instead of a result close to 18 for a wire of length 200cm. These were my anomalous results. This was probably due to the temperature variation of the wire. However these anomalous results were not big enough to change my final reading. I believe my results allowed me to cover a wide range of factors affecting the resistance of a wire, because I took a total of 4 lengths and eight readings for each length, giving me enough to analyse. I performed the experiment once, but I did take the reading of the current twice. Once in an ascending order, then in a descending order, thus I had two sets of results, which improved my accuracy. I also did a fair test because I followed the precaution of using the same equipment each time the experiment had to be carried out. Thus I can regard my results as being reliable values, as when compared to actual values, such as getting a 5 resistance for the 50cm wire as compared to supposedly having to get a 4. 5 resistance, or a 9. 83 resistance for a 100cm wire as compared to having to obtain a 9 resistance. I dont have any outstanding anomalous values that showed up on my graphs, only a few points did not quite fit on my line of best fit, which were quite close to it anyway. As I mentioned earlier these could have been caused by the heating effect of the equipment which resulted in slight variations of my readings. OTHER EXPERIMENTS TO MEASURE A CURRENT VOLTAGE RELATIONSHIP: Testing a silicon diode: I could connect a battery, a lamp, and a diode in series. Then connect the narrow end of the diode nearest to the negative terminal of the battery. Using an analog VOM type meter, I would set the meter to one of the lower ohms scales, say 0-2K, and measure the resistance of the diode both ways. If I get zero both ways, the diode is shorted. If I get INFINITY both ways, the diode is open. If I get INFINITY one way but some reading the other way (the value is not important) then the diode is good and I can measure the current and the voltage. As the graph shows, almost no current flows if the voltage applied is in the reverse direction. Testing the transistor: Testing a unijunction transistor (UJT) is a relatively easy task if you view the UJT as being a diode connected to the junction of two resistors, as shown in figure 4-21. With an ohmmeter, measure the resistance between base 1 and base 2; then reverse the ohmmeter leads and take another reading. Both readings should show the same high resistance regardless of the meter lead polarity. Connect the ohmmeters negative lead to the UJTs emitter. Using the positive lead, measure the resistance from the emitter to base 1, and then from the emitter to base 2. Both readings should indicate high resistances approximately equal to each other. Disconnect the negative lead from the emitter and connect the positive lead to it. Using the negative lead, measure the resistance from the emitter to base. From my mathematical deductions (to further prove my investigation) in my analysis section I calculated the value for resistivity for a nichrome wire and compared the calculated value with the actual standard value of rho. That is; LENGTH [cm] R from my experimental results R from my graphical results. REA [m] R from my experimental results [] R from my graphical results therefore; Material Length [m] Area [m ] Resistance [] Calculated [m] Standard [m] NichromeNichrome Nichrome NichromeÃ'Ž Thus we see that my results were not so different from the actual standard value of resistivity, and this is mainly because of the temperature variations that occurred during my experiment. This evidence does support a firm conclusion that if someone was to repeat the same investigation I would expect the to receive the same results. Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

In Support of Parenting Education Essay -- Child Development

In a perfect world, every child would be wanted and loved, and all parents would have the capacity and the desire to raise children who are healthy, mentally and physically strong, and displaying high moral integrity. Sadly, this is not the case. Some parents are, unfortunately, not much interested in what happens with their children. Other parents are not pleased with what is happening in the home with their children but do not know what to do to create effective change. Still other parents are unaware that there is another way, a better way, of parenting. Parent education could help in all of these scenarios. The literature demonstrates that parenting interventions improve the quality of the relationship parents have with the children as well as improving child social behavior (Scott, O’Connor, Furth, Mathias, Price, and Doolan 2010). Programs have been particularly effective when delivered to motivated, ethnic majority parents, but there has been little study of programs that serve as interventions aimed at preventing a wide range of poor outcomes associated with antisocial behavior, such as involvement in risky lifestyles, low school attainment, and a lack of satisfactory friendships (Scott et al.). There are, of course, problems associated with delivery of parenting programs; the greatest challenge is getting parents to participate when there is no mandate that they do so. Skilled personnel may be another issue; urban areas may have sufficient counselors and educators, but rural areas may not. A third issue is cost, although, as pointed out by Scott et al., â€Å"programs can i n theory be justified since in the long run they should reduce the high cost of antisocial behavior arising from increased use of services, higher levels... ...t effective when parents take an interactive part. Works Cited Brannon, Diana. â€Å"Character Education—a Joint Responsibility.† Education Digest 73.8 (2008): 56- 60. Parker, David C., Nelson, Jennifer S., and Burns, Matthew K. â€Å"Comparison of Correlates of Classroom behavior problems in schools with and without a school-wide character education program. Psychology in the Schools 47.8 (2010): 817-827. Reinberg, S. (2010). U.S. kids using media almost 8 hours a day. HealthDay News January 20, 2010. Retrieved from http://www.businessweek.com/lifestyle/content/healthday /635134.html Scott, Stephen; O’Connor, Thomas G.; Futh, Annabel; Mathias, Carla; Price, Jenny; and Doolan, Moira. â€Å"Impact of a Parenting Program in a High-Risk, Multi-Ethnic Community: the PALS Trial.† Journal of Child Psychology & Psychiatry 51.12 (2010): 1331-1341.

Discrimination at workplace based on gender and ethnicity

Imagine being stuck in the same job without proper compensations, or being thrown out of the job one fine day and being replaced by someone, you know hardly measures up to the fine standards you maintain, just because you do not look good, or you have physical ailments, or the other person is a pretty looking female, and you are a male, or simply because you are being replaced by a younger, ‘energetic’ person, whose age replaces your experience and competence.This is a thought that scares millions of workers and professionals as they set out for to earn their daily bread and feed their dependants. The thought that this day may be their last day at work and not due to their own fault can be a thought very scaring indeed. The ‘big boss’ literally rules your life and these are things that must change for the better. Is it fair to judge a person and his professionalism solely on the basis of his colour, age, sex, ethnicity, and sexual tendencies?How does it matt er whether I was born in Africa, India or New York; why should it matter if my skin is black, brown or white; is being 45 years old a crime; why should one be prejudiced against if he/she has feelings for the same sex. In the end it should be the professional competence and the attitude to success that should replace these trivial feelings. Work place discrimination encompasses a spectrum of situations.It may range from sexual discrimination to sexual harassment, even work place bullying. It is pertinent here to define three commonly misinterpreted terms, ‘unlawful discrimination’, ‘unlawful harassment’ and ‘workplace bullying’. As detailed on the Human Rights and Equal Rights Commission (HREOC) website, unlawful discriminations implies a deliberate attempt to sideline a person in favour of others solely because of his age, sex, religion, ethnicity or pregnancy status, and other factors outlined above.Similarly ‘unlawful harassmentâ€℠¢ has been defined in the same website as â€Å"Under federal and state legislation unlawful harassment occurs when someone is made to feel intimidated, insulted or humiliated because of their race, colour, national or ethnic origin; sex; disability; sexual preference; or some other characteristic specified under anti-discrimination or human rights legislation†. Work place bullying relates to â€Å"the repeated less favourable treatment of a person by another or others in the workplace, which may be considered unreasonable and inappropriate workplace practice.It includes behaviour that intimidates, offends, degrades or humiliates a worker†. In the text a more detailed analysis with suitable situations will be mentioned. There should not a ‘wrongful termination’, which is the dismissal of an employee, when he did not deserve it. Workplace discrimination on the basis of gender When a deliberate attempt is made to downgrade a person solely on the basis of gen der, and this goes against the contractual agreement, it constitutes a ground for appeal (Allison & Taylor, Inc). It may be intended directly or indirectly as unintended rules.It may be ‘Disparate Treatment Gender Discrimination’, where a person is treated differently simply because of his gender. An example of this could be a situation where a male employee gets a better pay package than his female counterpart on the unfounded premise that he works more than her. It may be the other way round, that a female secretary gets more leaves from the boss, while her male counterpart is denied any leave. A slightly more complex situation is that of ‘Disparate Impact Gender Discrimination’, where there is has been an unintentional process involved.This can be understood in the context of employment in the armed forces, where though the rules of entry may be the same for both the sexes, yet, for some particular situations, like war, special rules may have been set, s uch that it becomes difficult for female soldiers to qualify. There may be a frank situation of sexual harassment, where promotions are linked to gaining special favors, usually sexual in nature, from the person of opposite sex. As shown in the cine-film,† Disclosure†, where the female boss deliberately denies opportunity to the male professional, because he refused sexual favors.There may be harassment from the same sex, where in the female boss, feeling threatened sexually by the entry of a petite secretary or a colleague, deliberately insults her in front of others, in effect creating a ‘hostile environment’. There is an interesting entity known as ‘Quid Pro Quo Harassment (district attorney . com). This refers quiet simply to trade in terms of sexual favors. In this situation the availability of sex is the prime requisite to continue work. It may also mean, that the job is denied to a suitable candidate, if sexual favors are denied.A hostile enviro nment is one where the employee is challenged mentally and emotionally due to repeated exposure to offensive materials such as crude jokes, pornographic material (HREOC website). This does not allow the employee to settle down to the best of his/ her abilities. Of course, just because offensive language is used, or sexual advances are made, does not qualify simply as workplace discrimination. If such activities are carried out in concert with the said employee, there is no ground for case against the office.A female employee may readily consent to go out on a date with her colleague, but later if she alleges sexual harassment, this does not constitute ground for appeal. These are some situation of unlawful discrimination. There are other situations like prejudice in selecting a particular employee for promotion, or training, or dismissal. A female employee, doing the same work, may be receiving lesser pay. Under the Equal Pay for Equal Act (Safety. com) every person doing similar wo rk should be paid paid equally.An interesting aspect is that strictly speaking sex and gender are considered different by pure semantics (workplacefairness. org). Sex is anatomical identity of the person, while gender refers to how the person perceived himself/ herself. Other spectra of workplace discrimination. Discrimination on the basis of age – in the AARP website, a reference to the Age Discrimination in Employee’s Act (ADEA) is mentioned. According to the law, if discrimination has been done to a person above 40 years of age on the basis of his age, it is illegal.It may be in the form of not being selected for the job inspite of being qualified in favor of a younger person, or it may be denial of promotions on the basis of age. Such a situation may also arise if the older employee is dismissed by the company in favor of a younger person, so that the new employee is paid less. A larger number of Racial discrimination – The colour of the skin of the person, or the company a person keeps, should never constitute grounds for prejudice. Action against someone for dating a person of different culture, constitutes grounds for appeal (www.districtattorney. com).Pregnancy and marriage discrimination- pregnancy is a temporary disability and is considered so (workplacefairness. org). Any discrimination on the above is wrong and punishable by law. If a female employee is treated differently because of her marriage than one who is married, the affected employee is right in taking action against the employer. Discrimination on basis of nation of origin. In the United Stated, only federal reserved jobs can be advertised as â€Å"for US Nationals Only†.Any other job is open for any individual who has gone through the mandatory requirements of the US Government (districtattorney. com) The opposing view Till now we have considered numerous points against the policy if discrimination, but to better understand the complex situation, a point in fa vour may also be taken, and indeed valid arguments may be put up. For example, any firm, be it government or private, has the right to employ the best professionals in order to further its interests.Thus if the company feels, that a person is getting old, and does not enthuse the same enthusiasm as he used to, it may be argued that it is within its rights to employ someone it feels is young and dynamic and ready to face challenges. It thus breeds a feeling of intense competition that brings out the best in the professional, forcing him to work better. This ‘on the edge’ feeling will foster a will to perform better. Hazardous jobs like army, fire fighting service and the police, need tough physical labour and often there is a real threat to the personnel.It is a fact that men are physically better equipped to face these situations. Thus these institutions may feel that by getting only the best for the job, will help important services like the army and police perform the tasks of fighting and security better. Again the company may feel, that a lady who is pregnant, or who has delivered recently, will not be able to give the commitment that is required. Long hours that a company demands, may not be possible fort the lady. Thus this situation can be argued both ways Summary. It is inhuman to deny a human being the opportunity to succeed in life, and prove himself.Thus why it should make a difference that he is black, or white, or he is above forty, especially when the person is qualified for his position, is incomprehensible. No argument is possible to defend someone who denies a job to a woman, just because she is married, or has delivered. Pregnancy is a universal truth, how can society be so cruel. All said and done, work place discrimination is a blot on the very existence of society, and all measures, be it legal, or legislative must be taken to ensure that this does not take place.

Biography of Ivan the Terrible, First Tsar of Russia

Ivan the Terrible, born Ivan IV Vasilyevich (August 25, 1530 – March 28, 1584), was the Grand Prince of Moscow and the first Tsar of Russia. Under his rule, Russia transformed from a loosely connected group of individual medieval states into a modern empire. The Russian word translated â€Å"terrible† in his name carries positive connotations of being admirable and formidable, not evil or frightening. Fast Facts: Ivan the Terrible Full Name:  Ivan IV VasilyevichOccupation: Tsar of RussiaBorn: August 25, 1530 in Kolomenskoye, Grand Duchy of MoscowDied: March 28, 1584 in Moscow, RussiaParents: Vasili III, Grand Prince of Moscow, and Elena GlinskayaSpouses: Anastasia Romanovna (m. 1547-1560), Maria Temryukovna (m. 1561-1569), Marfa Sobakina (m. October-November 1571), Anna Koltovskaya (m. 1572, sent to monastery).Children: 3 daughters and 4 sons. Only two survived to adulthood: Tsarevich Ivan Ivanovich (1554-1581) and Tsar Feodor I (1557-1598).Key Accomplishments: Ivan IV, aka Ivan the Terrible, was the first tsar of a united Russia, previously an assortment of duchies. He expanded Russian borders and reformed its government, but also laid the foundation for absolute rule that would eventually bring down the Russian monarchy, centuries later. Early Life Ivan was the eldest son of Vasili III, Grand Prince of Moscow, and his second wife Elena Glinskaya, a noblewoman from the Grand Duchy of Lithuania. Only the first few years of his life were anything resembling normal. When Ivan was only 3 years old, his father died after an abscess on his leg led to blood poisoning. Ivan was named the Grand Prince of Moscow and his mother Elena was his regent. Elena’s regency only lasted five years before she died, most likely in a poisoning assassination, leaving the realm in the hands of feuding noble families and leaving Ivan and his brother Yuri alone. The struggles that Ivan and Yuri faced are not well documented, but what is certain is that Ivan had very little power of his own growing up. Instead, politics were handled by the noble boyars. Upon turning sixteen, Ivan was crowned at the Cathedral of the Dormition, the first ruler to be crowned as â€Å"Tsar of All the Russias† rather than as a Grand Prince. He claimed ancestry going back to Kievan Rus, an old Russian kingdom that had fallen to the Mongols centuries earlier, and his grandfather, Ivan III, had consolidated many Russian territories under Moscow’s control. Expansions and Reforms Only two weeks after his coronation, Ivan married Anastasia Romanova, the first woman to bear the formal title of tsarina and a member of the Romanov family, who would come to power after Ivan’s Rurik dynasty faltered after his death. The couple would go on to have three daughters and three sons, including Ivan’s eventual successor, Feodor I. Almost immediately, Ivan was faced with a major crisis when the Great Fire of 1547 swept through Moscow, devastating huge portions of the city and leaving thousands dead or homeless. Blame fell on Ivan’s maternal Glinski relatives, and their power was all but destroyed. Aside from this disaster, however, Ivan’s early reign was relatively peaceful, leaving him time to make major reforms. He updated the legal code, created a parliament and a council of nobles, introduced local self-government to rural areas, founded a standing army, and established the use of the printing press, all within the first few years of his reign. St. Basils Cathedral in Moscow is one of the iconic images of Russia to this day. WorldWide Images /  Getty Images Ivan also opened up Russia to a certain amount of international trade. He allowed the English Muscovy Company to access and trade with his country and even struck up a correspondence with Queen Elizabeth I. Nearer to home, he took advantage of pro-Russia sentiments in nearby Kazan and conquered his Tatar neighbors, leading to annexation of the entire Middle Volga region. To commemorate his conquest, Ivan had several churches built, most famously St. Basil’s Cathedral, now the iconic image of Moscow’s Red Square. Contrary to legend, he did not force the architect to be blinded after completing the cathedral; architect Postnik Yakovlev went on to design several other churches. Ivan’s reign also saw Russian exploration and expansion into the northern region of Siberia. Increased Turmoil The 1560s brought major turmoil both domestically and internationally. Ivan launched the Livonian War in an unsuccessful attempt to gain access to the Baltic Sea trade routes. At the same time, Ivan suffered personal losses: his wife Anastasia died in suspected poisoning, and one of his closest advisors, Prince Andrei Kurbsky, turned traitor and defected to the Lithuanians, destroying a region of Russian territory. In 1564, Ivan announced he intended to abdicate due to these ongoing betrayals. Unable to rule, the boyars (nobles) begged him to return, and he did so, under the condition that he be allowed to become an absolute ruler. Upon returning, Ivan created the oprichnina, a sub-territory that owed allegiance solely to Ivan, not to the government as a whole. With the help of a newly-formed personal guard, Ivan began persecuting and executing the boyars who he claimed were conspiring against him. His guards, called oprichniks, were given the lands of the executed nobles and were not held accountable to anyone; as a result, the lives of the peasantry suffered greatly under their new lords and their subsequent mass exodus drove up the prices of grain. Ivans Oprichniki reported only to him (Painting by Nikolai Nevrev, circa 1870). Wikimedia Commons Ivan eventually remarried, first to Maria Temryukovna in 1561 until her death in 1569; they had a son, Vasili. From then on, his marriages were more and more disastrous. He had two more wives who were officially married to him in the church, as well as three unsanctioned marriages or mistresses. During this period, he also launched the Russo-Turkish War, which lasted until a 1570 peace treaty. That same year, Ivan carried out one of the lowest points in his reign: the sacking of Novgorod. Convinced that the citizens of Novgorod, who were suffering from an epidemic and a famine, were planning to defect to Lithuania, Ivan ordered the city destroyed and its citizens captured, tortured, and executed on false charges of treason–including children. This atrocity would be the last stand of his oprichniks; in the Russo-Crimean war of 1571, they were disastrous when faced with a real army and were disbanded within a year or so. Final Years and Legacy Russia’s conflicts with its Crimean neighbors continued throughout Ivan’s reign. In 1572, however, they overextended themselves, and the Russian army was able to decisively end the hopes of Crimea—and their patrons, the Ottomans—to expand and conquer into Russian territory. Ivan’s personal paranoia and instability grew as he aged, leading to tragedy. In 1581, he beat his daughter-in-law Elena because he believed she had dressed too immodestly; she may have been pregnant at the time. His eldest son, Elena’s husband Ivan, confronted him, frustrated over his father’s interference in his life (Ivan the elder had sent both of his son’s prior wives to convents when they failed to produce heirs immediately). The father and son came to blows, with Ivan accusing his son of conspiracy, and he struck his son with his scepter or walking stick. The blow proved to be fatal, and the tsarevich died a few days later, to his father’s intense grief. Painting by Vyacheslav Schwarz of Ivan beside his dead son Ivan, circa 1864. Wikimedia Commons / The York Project   In his final years, Ivan was plagued by physical weakness, nearly unable to move at some points. His health deteriorated, and he died of a stroke on March 28, 1584. Since his son Ivan, who had been trained for ruling, was dead, the throne passed to his second son, Feodor, who was an unfit ruler and died childless, leading to Russia’s â€Å"Time of Troubles† that would not end until Michael I of the house of Romanov took the throne in 1613. Ivan left behind a legacy of systemic reform, laying the groundwork for the Russian state apparatus going forward. His obsession with conspiracy and authoritarian rule, however, also left a legacy of imperial absolute power and autocracy, which, centuries later, would chafe the Russian population to the point of revolution. Sources Bobrick, Benson. Ivan the Terrible. Edinburgh: Canongate Books, 1990.Madariaga, Isabel de. Ivan the Terrible. First Tsar of Russia. New Haven; London: Yale University Press, 2005.Payne, Robert, and Romanoff, Nikita. Ivan the Terrible. Lanham, Maryland: Cooper Square Press, 2002.