The Thevenin equivalent resistance Essay Example

The Thevenin equivalent resistance Paper When using a voltage or current that varies, certain components that would not work with a direct current become functional. The capacitor is this type of component. It is made up of two conducting pieces of material that are a small distance apart and are separated by an insulator (or dielectric). The following experiments will show the way in which the capacitor works when placed in a working circuit in different combinations with a resistor. They will show how the time constant can be calculated experimentally as well as theoretically. One of the most underlying laws when dealing with electronics, which was introduced by Georg Ohm in 1821 [Gough], is Ohms Law. These experiments will validate this law. It will also investigate how the characteristics of a circuit may change when introducing resistors in parallel or series and as a result, verify the voltage divider rule. They will look at voltage drops around complete loops and how by manipulating a circuit can be used to make complex networks simpler, thereby validating Kirchoffs Voltage and Current Laws, and Thevenins Theorem. The Wheatstone bridge circuit was developed in 1843 by Charles Wheatstone in order to determine the values of unknown resistances [Gough], This will be investigated to check the validity of the Wheatstone bridge theory and prove its usefulness. Theory Experiment P-IE-R-1 (Ohms Law) Ohms Law indicates that the current through a conductor is proportional to the difference in potential between its ends. This, in equation form, is shown by V=I R (V is potential difference, I is the current and R is the constant of proportionality, or resistance). We will write a custom essay sample on The Thevenin equivalent resistance specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on The Thevenin equivalent resistance specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on The Thevenin equivalent resistance specifically for you FOR ONLY $16.38 $13.9/page Hire Writer So if a current is passed through a circuit with an unknown resistance, this resistance can be calculated by plotting a graph of voltage against current. This should produce a straight line with a slope equalling the value of R. Experiment P-IE-R-2 (Resistor Networks) If a number of components are connected so that the current through each of them is equal then they are connected in series. So if you have two resistors connected in series, as shown below in Figure 1, then V1 = R1 I and V2 = R2 I. If you total all the separate potential differences around the circuit in Figure 1, then the sum will be 0, this is true for any complete loop in a circuit. It is known as Kirchoffs Voltage Law. As a result of this, each value of resistance can be combined to give an equivalent resistance, referred to as Req, this has no effect on the characteristics of the circuit. However, the components within a circuit can be connected up so that the potential difference across each of them is identical. This is a parallel connection. The two resistors in Figure 2 show components in parallel. The current of each is given as I1 = V/R1 and I2 = V/R2. As charge is conserved, it can be said the amount of current going into a node is equal to the total amount that leaves it, i. e. the sum of the currents is 0 (This is known as Kirchoffs current law). Therefore, the amount of current that passes through the two resistors in Figure 2 has to be equal to the current that is generated by the supply. It can be expressed as I = I1 + I2. By manipulating this equation and applying Ohms law, the equivalent resistance of the circuit can be calculated using the following equation 1/Req = 1/R1 + 1/R2. But when there are only two resistors it can be written as Req = R1 R2 / (R1 + R2), this is known as the product over the sum rule. Experiment P-IE-R-3 (Kirchoffs Laws and Thevenin Resistor Networks) Kirchoffs Laws: As mentioned above, Kirchoffs Voltage Law is defined as The algebraic sum of the potential differences around any complete loop of a circuit is zero [Gough]. Therefore if you refer to Figure 1, V = V1 + V2. But as Figure 2 indicates, current flows into the positive side of a resistor but at the same time out of the positive terminal of an emf source. As a result potential difference can be called the Voltage Drop. Also mentioned above, Kirchoffs current law can be defined as the algebraic sum of the currents into any node is zero [Gough]. So where three or more conductors connect the total current through the node will equal the current from the supply. Referring back to Figure 2, this can be shown by writing I = I1 + I2. Thevenins Theorem Thevenins Theorem can be defined as any network of resistors and batteries having two terminals is equivalent, as far as its terminal behaviour is concerned, to the series combination of a resistor and a DC voltage supply. [Gough] With a Voltage divider (Figure 3), by moving the switch to certain possible connections, different fractions of the supply can be created at the output. So if the switch is connected to the point B as shown, the output voltage can be obtained using the formula Vout = I R3. The current can be calculated by first working out the total resistance of the circuit and then by using Ohms law. If a load resistance is put across the output terminals as shown in Figure 3, then the current in the circuit will no longer be the same. The new value for the current will now be obtainable by using the formula I = V (R3 + RL)/ RL (R1 + R2 + R3) + (R1 + R2) R3. If a load is connected across Vout, then the current through the load resistance will be given by IL = Vout/RL. This shows that by using a combination of Ohms law and Kirchoffs Current and Voltage Laws, more complex circuits can be analysed faster and more easily. Experiment P-IE-R-4 (The Wheatstone Bridge) As Figure 4 shows the unknown resistor is R4, the other resistances, apart from R5, are known and can be a combination of different values. This circuit works by varying the resistance of R1, R2 and R3 so that the current through R5 is equal to zero. When the circuit is in this situation the bridge is known to be balanced. The value of the unknown resistor can then be worked out by using the values of the now known resistors. By using Thevenins theorem the current through R5 can be found by changing the rest of the circuit to its Thevenins equivalent, this gives the circuit shown in Figure 5. The Thevenin equivalent resistance (RT) across DB is ascertained by connecting these two parallel resistor combinations across R5, giving the Formula: RT = (R1 R3/ R1 + R3) + (R2 R4 / R2 + R4) The Thevenin equivalent voltage is determined by measuring the potential difference between the points D and B without R5 connected. As there are two parallel combinations of resistors, the voltage through each of them will be equal. This Voltage will be equal to the one that is driving the circuit, i. e. V, therefore the equivalent Thevenin Voltage can be obtained by using the formula VT = VDB = V [(R1 / {R1 + R3}) (R2 / {R2 + R4})] So I5 can be worked out using the Thevenin equivalent Voltage and resistance along with R5. The bridge is balanced when VT is equal to zero.

Authoritative Leadership Style

Authoritative Leadership Style Leadership is the process through which an individual gathers and earns support of others through social enlistment so that they can work together to achieve set goals and objectives. An organization can adopt different forms of leadership styles depending on its needs and requirements.Advertising We will write a custom essay sample on Authoritative Leadership Style specifically for you for only $16.05 $11/page Learn More To have a clear understanding of my leadership style, I used several online assessment tools. The assessment tool provided by OSP (2008) revealed by leadership style to be authoritative. According to this tool, my leadership style was characterized by giving tight direction to my subordinates, encouraging communication to flow in one direction and exercising minimal delegations. However, the assessment tool provided by Galford and Maruca (2012) clearly explained my leadership style. The results that were arrived at after the assessment stat ed that I was an ambassador, an advocate, a people’s mover and a creative builder. These descriptions are in line with the supporting leadership style; I usually implement in all the activities and projects that I lead. According to this leadership style, a leader is friendly to the team members and employees of lower levels. He/she offers support to his subordinates and provides minimal directions in a working environment. This in turn makes the employees to feel comfortable at a work hence perform their roles and duties to the best of their abilities to achieve the goals and objectives of the project as well as their own personal goals and objectives. Additionally, this form of leadership style encourages teamwork and provides the best environment for starts to flourish in their respective careers.Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Communication Communicatio n is an essential aspect in the running and management of an organization. Therefore, the HR department needs to ensure that efficient communication mechanisms have been put in place to ensure that precise information flows at all levels of management (Khan, 2011). To determine my style of communication, I used a number of online assessment tools. The assessment tool provided by Russo (2012) revealed my communication style to be assertive but its description of vague. On the other hand, the assessment tool provided by CEDA (2012) clearly explained my communication style. Although the tool revealed my communication style to be assertive, it also stated that am an individual who stands up for my rights and the rights of my subordinates, respect all my team members and treasure the respect that they give me. From all this, the tool concluded that I possessed relater communication skills. Team Management For an organization to achieve its goals and objectives, it needs to understand and take advantage of the strengths of its employees. Additionally, an organization also needs to work and improve on the weaknesses of its workforce. Thus, it is essential for the management of an organization to understand the personality of every team member. The Myers Briggs Type Indicator is an effective personality assessment tool that can be used to gauge the personality, strengths, and weaknesses of team members within an organization (MBTI, n.d.). This assessment tool has sixteen indicators that are used to gauge the personality of an individual. For the management to determine the strengths and weaknesses of an individual, it can use the results. Furthermore, the results can be used to enhance the team spirit of an organization hence making it easier to achieve the goals and objectives of the project. On the other hand, the temperament method can be used to assess the personality of team members. This method focuses on specific characteristics of an individual such as the act ions of an individual, styles of communication, the talent that they posses and their values (Keirsey.com, n.d.).Advertising We will write a custom essay sample on Authoritative Leadership Style specifically for you for only $16.05 $11/page Learn More From the analysis of these traits, the personality of an individual can be interpreted as idealistic, rational, artisan or guardian. This however depends on the impacts that an individual has on the project and the specific role that he/she plays and his/her strengths and weaknesses. References CEDA (2012).  Communication Styles.  Retrieved from cedanet.com/meta/communication_styles.htm Galford, R. and Maruca, F. (2012).  Your Leadership Legacy.  Retrieved from yourleadershiplegacy.com/assessment/assessment.php Keirsey.com (n.d.).  Overview of the Four Temperments.  Retrieved from keirsey.com/4temps/overview_temperaments.asp Khan, A. (2011).  Informal Communication Styles Benefit Mcdonald’ s and Ford: The Way  Ahead In an Era Of Social Networking.  Retrieved from emeraldinsight.com/journals.htm?articleid=1958608 MBTI (n.d.).  MBTI Basics.  Retrieved from myersbriggs.org/my-mbti-personality-type/mbti-basics/ OSP (2008).  Leadership Style Self Assessment.  Retrieved from performancesolutions.nc.gov/developmentinitiatives/CareerDevelopment/Assessments/docs/LeadershipStyle.pdfAdvertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Russo, E. (2012).  Whats My Communication Style. Retrieved from hrdqstore.com/Whats-My-Communication-Style-Assessment.html

Exercises Week 2 Essay Example | Topics and Well Written Essays - 1000 words

Exercises Week 2 - Essay Example Hence this will be the preferred investment, as the return is substantial and the risk is the lowest. c. If Sharon were risk – seeking, she would prefer the investment with the highest risk, unless a higher return is promised for a lower risk rate. In this case, investment X has a higher return for a lower risk. Also, investment Y has a return of 12%, same as that of the current return. Investment Y will also be preferred due to the risk seeking attitude. d. Based on the traditional risk preference behaviour exhibited by financial managers, the most preferred investment would be investment X. The main reason is that it has the lowest risk per unit of return (7%/14%) of 0.5 which is the same as that of the current investments of the firm. It is evident that the most likely values for both the options are the same. However, the worst case scenario for expansion A is a 16 % return whereas that of Expansion B is 10 %. Also, the return for expansion A lies within + 4 % of the most likely return of 20 %, whereas it is +8 % for expansion B. Hence the less risky project is Expansion A. c. If given the choice, I would prefer to take up the Expansion A, as it has lesser risk and the most likely return is the same as that of the high risk Expansion B. This certainly implies that I have a risk - averse behaviour. d. If the most likely outcome is 21% for expansion B, I would still prefer to opt for expansion A. the main reason is that the risk associated with expansion A is much lesser and the pessimistic outcome is very close to the most likely outcome. d. The expected return is the highest at 17.5 % for the portfolio 1 containing 100% of asset F compared to that of the other two alternatives. It is also evident that the three investment portfolios have the same risk associated with the returns. The coefficient of variation (return per unit of risk) is also higher for portfolio 1. Hence it is clear that

WEP 300 Essay Example | Topics and Well Written Essays - 500 words

WEP 300 - Essay Example According to several experiments in laboratories, classrooms, organizational workplaces and other environments, rewards essentially weaken the very basis of interventions they are meant to support (Pink 1). The findings show that the inability of any particular incentive program can be attributed more to the insufficiency of the emotional assumptions upon which such plans are based than the seemingly botched approach taken to implement the incentive. As such, Pink (6) noted that monetary incentives blunt individual creativity. The researcher based his reasoning on economics and psychology studies. He cited the â€Å"Candle Problem† experiment by Karl Duncker, which was invented in 1945 to examine â€Å"functional fixedness† in human reasoning. The outcomes support the inefficiency of incentive-based human resource management. Duncker proved that it is not easy for an adult to solve issues facing him or her by summoning an out-of-the-box mentality. This is because humans are not bound to â€Å"iterate(ing) something new† (Pink 8). This means can be construed the general human reluctance to experiment with new objects in an innovative manner. Similarly, Sam Glucksberg repeated the experiment in1962, but focused on the impact of monetary inducements on creativity. He established that financial incentives may actually worsen the problem of fixedness in employee thinking and functions. As such, Pink noted that a Candle Problem experiment conducted on two sets of sample employees working as a team to find a solution established that there are modest impacts of incentives on creativity between the group that was subject to incentives and the other that was not (7). However, the outcomes showed no undesirable consequence of incentives. Therefore, it can be argued that the average performance of employees is marginally better when creativity is based on incentives, but the variation is not

How the book house rules reflects upon how a boy in a family lives Essay

How the book house rules reflects upon how a boy in a family lives with asburgers and itellectual challanges - Essay Example In her all absorbing efforts to normalize the elder child, the younger one is thoroughly neglected and he grows up to be a rebel and a thief. The various Asperger syndromes have been clearly shown. The mother’s anguish is visible through her own words. She wants to be a good mother and neutralize her kid’s life as much as possible; still she grieves at each moment when she fails in her attempts. The brother of the AS kid also draws our sympathy in spite of the negative image created by him. He is very miserable in life with an absentee father, an abnormal brother, a busy mother and no money to fund his amusements. His soul cries out for love and happiness and to find out happiness he peaks into happy families. With the passage of time, he becomes bolder in his endeavors and starts house breaking in the absence of the owners and stealing stuff that his mother can’t afford. He feels burdened with having to look after his brother and irritated at having his needs me t before his own. While, the AS child is given all the facilities and care, the normal child is left to his devices. Thus, we find different people reacting in different manner towards Asperger Syndrome that starts from fear and shirking of responsibility (father), over protective attitude (mother), to a feeling of resentment and burdened (brother). House Rules also reflects on the inefficiency of the legal system when dealing with people facing some physical or psychological disability. The legal system is created on the basis of normal citizens and when an abnormal individual falls in its periphery then it become increasingly difficult to save his soul. The judiciary system has been inadequately created to mistrust all abnormal people. There is no word such as â€Å"abnormality† in their dictionary. They would deal with an AS person in the same way as an ordinary individual showing no empathy whatsoever. Thus, over and above the House Rules deals with the trauma of a suffer ing family that has a child with Asperger Syndrome and the inadequate justice system reigning in the country. Asperger syndrome is an autism spectrum disorder where the patient has difficulty in social interaction. The sufferer also show restricted and repetitive pattern of interest and behavior. This disorder is difficult to diagnose as the cognitive and linguistic development are preserved and are almost equal to a normal person. Hence, most of the time this disorder goes unnoticed. In fact, not many people are aware of this disorder and this is the reason that the sufferers do not get the empathy and treatment that they deserve. Jacob Hunt, the central character of the book suffers from this order and has to face several difficulties (besides the obvious ones) because of it. Jacob Hunt is an eighteen years old boy who lives with his mother, Emma Hunt and brother, Theo Hunt. His father had run away soon after Theo’s birth when he had been made aware of his first childâ€⠄¢s condition. Jacob is an intelligent individual with a very sharp mind but his drawback is that he is suffering from Asperger’s Syndrome and is hopeless at expressing himself and reading social cues. Jacob’s highly intelligent mind is revealed by his mother’s words in the first chapter itself: I’ve met so many parents of kids who are on the low end of the autism spectrum, kids who are diametrically opposed to Jacob,

Synthesis of Chloropentaamminecobalt (iii) Chloride

Synthesis of Chloropentaamminecobalt (iii) Chloride Introduction Cobalt was discovered by Georg Brandt in 1735 interestingly the name Cobalt originates form the German word Kobald which means goblin or evil spirit. The original use of cobalt was value to early civilisation of Egypt for colouring glass blue. Alfred Werner was a pioneer in coordination Chemistry determined the isomer cobalt (III) hexamine chloride. Experimental Ammonium chloride (1.306g) was dissolved in concentrate ammonia solution (10.5cm3) forming a colourless solution. Colablt(II)chloride hexahydrate (2.494g) was added in small portions with t stirring producing a muddy liquid with a dark precipitate. 27% Hydrogen peroxide (2.25cm3) was added using a dropping pipette with constant stirring. A small amount of heat and effervescence (bubbling) was visible. Once the reaction has stopped and a dark red solution was formed to which Concentrate Hydrochloric acid (10cm3) was added very slowly with constant stirring. A large amount of heat was released and a white gas was given off forming a dark pink solution. This solution was heated for 18mins before being cooled in ice forming dark pink precipitate. The solution was filtered and washed with dilute hydrochloric acid (5cm3) ethanol (5cm3) and acetone (5.5cm3). Once dry the crystals (1.447g %) were transferred to an open sample vial and dried in a desiccator for a week. A portion of this product (g) was dissolved in Dilute ammonia (10cm3), water (40cm3) was added. The solution was heated (15 mins) forming a clear red solution. Concentrate Hydrochloric acid ( 10cm3) was added followed by Ammonium chloride (1.00g) forming a orange solution. The resulting solution was heated for a further 25mins. COLOURS . Solution was cooled in ice and the product filtered off and washed with hydrochloric acid (5cm3) ethanol (5cm3) and acetone (5.5cm3). Forming 0.g %) Ammonium chloride(5.02g), Cobalt(II) chloride hexahydrate(1.396g) and Sodium Iodide (0.192g) were dissolved Water (10cm3) producing a deep pink purple colour. Powdered iodine (0.718g) was added forming a colour. Concentrate Ammonia (5.2cm3) was added with stirring forming a light muddy brown grey then turned greyer on after a further 30mins of stirring. The resulting solution was left to stand for 1 min and then the liquid was decanted off, water (20cm3) was added and decanted off and then Ethanol (20cm3). The resulting precipitate was dried under suction with further Ethanol washings (15cm3) producing (1.404g %) Ammonium Chloride (1.0g) was dissolved in Boling water (3.5cm3). Cobalt(II) chloride hexahydrate (1.548g) was added producing a deep royal blue solution. Charcoal (?0.75g) was added turning the solution grey black. The solution was cooled in an ice bath to 5oC and Concentrate Ammonia (4.5cm3) was added in small portions over 3 mins. Hydrogen peroxide (23% vol) (4cm3) was added in portions over 5 mins. The solution was then heated to 60oC for 1 min. The solution was re cooled to 3oC in an ice bath. The black oily precipitate was filtered under suction before being added to Boiling water (12cm3). Concentrate Hydrochloric acid (0.5cm3) was added and then the solution filtered. Concentrate Hydrochloric acid (2cm3) was added to the filtrate (liquid) and the solution cooled in ice. The resulting orange precipitate was filtered and washed with acetone (10cm3) producing (0.444g %) Results and discussion Equations ΔM= Molar Conductivity (S m2 mol L-1) = Measured conductivity (units S m-1) c = Concentration (units mol m3) A mol L-1 = A x100 mol m3 A  µS cm-1= (A /10000) S m-1 n=M/Mr n= Moles M= Mass (units grams) Mr = Molecular weight n= C x V n = moles C = Concentration (units mol L-1) V= Volume (L) 100cm3= 0.1L Preparation of Chloropentaamminecobalt (III) chloride Ammonium chloride +Ammonia+ Cobalt (II) chloride hexahydrate à   Chloropentaamminecobalt (III) chloride NH4Cl + CoCl2.6H2O + NH3 à   [Co(NH3)5Cl]Cl2 Calculation of Concentration of Chloropentaamminecobalt(III) chloride in 100cm3 volumetric flask n=M/Mr M= 0.1100g Mr Chloropentaaminecobalt(III) chloride = 267.4762 n = 0.1100/267.4762 n= 4.112543110-4 n=CV 4.1125431 x10-4= C x 0.1 C= 4.1125 x10-3mol L-1 à   0.41125 mol m3 Conductivity = 1286 µS à   0.1286 S m-1 S m2 mol L-1 Preparation of iodopentaaminecobalt(III) chloride Iodine + Cobalt(II) Chloride hexahydrate + Ammonia+ Ammonium chloride à  Iodopenaaminecobalt(III) chloride I2 + CoCl2.6H2O + NH4Cl + NH3 à   [Co(NH3)5I]Cl2 n=M/Mr M= 0.0934g Mr iodopentaaminecobalt(III) chloride = 341.90 n = 0.0934/341.90 n= 2.73179 x10-4 n=CV 2.7317910-4= C x 0.1 C= 2.7317929 x10-3mol L-1 à   0.27317929 mol m3 Conductivity = 1137 µS à   0.1137 S m-1 S m2 mol L-1 Preparation of hexaaminecobalt(III) chloride Ammonium chloride + Cobalt(II) chloride hexahydrate +Ammoniaà   Hexaamminecobalt(III) chloride. NH4Cl + CoCl2.6H2O+ NH3 à   Co(NH3)6]Cl3 n=M/Mr M= 0.1010g Mr Hexaamminecobalt(III) chloride =267.4762 n = 0.1010/267.4762 n= 3.776036896 x10-4 n=CV 3.776036896 x10-4= C x 0.1 C= 3.776036896 x10-3mol L-1 à   0.3776036896 mol m3 Conductivity = 1720 µS à   0.1720 S m-1 S m2 mol L-1

Abusing the Force Essays -- Law Enforcement Social Issues Police Essay

Abusing the Force The fundamental purposes of law enforcement is the serve and protect the individuals of society. Rough treatment is often times afflicted upon unruly citizens as an alternative reform of discipline. Police abuse remains one of the most serious and divisive human rights violations of today. The secrecy, stress, and dangers of police work leads to an insular and close-knit occupational culture that results in a strong distinction between members of the police and society. An in-depth investigation on police brutalization and its causes of corrupting within the 1991 beating of Rodney King is evaluated by means of the credibility within the rights of citizens in Canada and the United States, the effects from prejudice affliction, and the societal disparagement on morals of the cultures in policing. Corruption is both a result and cause of the separation of the police from society. The isolation of the police can lead to a divergence of the values of law enforcement officials from those that the rest of society professes to uphold (McAlary, 1997). The early morning of March 3, 1991 illustrates the horrific crime in Los Angeles, California. Several California Highway Patrol cruisers chase Rodney King, a robbery parolee, speeding over 110 miles per hour down the Los Angeles strip. King, an African American, is eventually forced to stop after running through several red lights at intersections. As the other two passengers of the car complies with police requests to exit the car and are subdued with minor resistance, King refuses to exit the car, thus a beating is administered by three Caucasian officers at the order of their sergeant who is on the scene. He is subsequently stricken over 56 times by wielding PR 24 metal batons, kicked at least 6 times, and shot twice with a Taser el ectronic stun gun, holding over 50,000 volts of electricity per shot (Lepour, 1991). Additionally, twenty-three other officers stand watching on the scene in which none made effort or suggestion to stop the crude combat. Consequently, King suffers extensive injuries including skull fractures, broken bones, and nerve damage to his face and body. Meanwhile, George Holiday, one of the several civilian by-standees awaken by noises of the police helicopter and sirens, videotapes the initial beating from his nearby apartment. Twelve days later, the three police officers ... ...r peers from the rest of society. The division may be further entrenched by a perception on the part of some officers of public animosity towards the police (Will, G. F., 1998). Every instance of corruption is further reinforces the distance between society and the police by increasing public hostility and distrust towards the police. Policing is an extremely emotional occupation and it is difficult for officers not to involve personally in their work. They are not merely human forms of robots, firing their guns arbitrarily with a complete lack of sense or emotion. No matter what type of activities police officers are involved in, they are often required to use force to rectify certain situations, thus this primary discrepancy is difficult to distinguish between what is required and what is excessive force. As long as police officers play by the rules of their peer group and the public continues to negatively label them, any rapprochement between the two is unlikely. Fundamentally, police officers rely primarily on instinct and as long as their basic intention is to promote good and not evil while citizens need to trust that the instincts of an officer are generally correct.