The reason for which the resistance is given by
Answer to Problem 1ASA
The resistance of a circuit is the ratio between the voltage measured by the voltmeter and the current measured by the ammeter. So the resistance is given by
Explanation of Solution
The potential difference through an electric circuit is measured by using the voltmeter and the amount of flow of current through the circuit is measured by using the ammeter. The ammeter-voltmeter method is used to measure the resistance of the circuit.
Conclusion:
The Ohm’s law is used to measure, current, voltage, and resistance of a circuit if either two of them are given.
Write the expression for Ohm’s law.
Here,
Rearrange the above expression for
Want to see more full solutions like this?
Chapter 24 Solutions
Physics Laboratory Experiments
- The severity of a shock depends on die magnitude of the current through your body. Would you prefer to be in series or in parallel with a resistance, such as the heating element of a toaster, if you were shocked by it? Explain.arrow_forwardUsing an ohmmeter, a student measures the resistance between various points on his body. He finds that the resistance between two points on the same finger is about the same as the resistance between two points on opposite hands-both are several hundred thousand ohms. Furthermore, the resistance decreases when more skin is brought into contact with the probes of the ohmmeter. Finally, there is a dramatic drop in resistance (to a few thousand ohms) when the skin is wet. Explain these observations and their implications regarding skin and internal resistance of the human body.arrow_forwardFor the circuit shown in Figure P28.55. the ideal voltmeter reads 6.00 V and the ideal ammeter reads 3.00-k. Find (a) the value of K, (b) the emf of the battery, and (c) the voltage across the 3.00-kft resistor.arrow_forward
- When resistors with different resistances are connected in series, which of the following must be the same for each resistor? Choose all correct answers, (a) potential difference (b) current (c) power delivered (d) charge entering each resistor in a given lime interval (e) none of those answersarrow_forwardThree 60.0-W, 120-V lightbulbs are connected across a 120-V power source, as shown in Figure P18.50. Find (a) the total power delivered to the three bulbs and (b) the potential difference across each. Assume the resistance of each bulb is constant (even though, in reality, the resistance increases markedly with current). Figure P18.50arrow_forwardReview. When a straight wire is warmed, its resistance is given by R = R0,[1 + a(T T0)] according to Equation 27.20, where a is the temperature coefficient of resistivity. This expression needs to be modified if we include the change in dimensions of the wire due to thermal expansion. For a copper wire of radius 0.100 0 mm and length 2.000 m, find its resistance at 100.0C, including the effects of both thermal expansion and temperature variation of resistivity. Assume the coefficients are known to four significant figures.arrow_forward
- Consider the circuit below. The battery has an emf of = 30.00 V and an internal resistance of r = 1,00 . (a) Find the equivalent resistance of the circuit and the current out of the battery. (b) Find the current through each resistor, (c) Find die potential drop across each resistor, (d) Find the power dissipated by each resistor, (e) Find the total power supplied by the batteries.arrow_forwardThree identical 60.0-W, 120-V lightbulbs are connected across a 120-V power source as shown in Figure P28.72. Assuming the resistance of each lightbulb is constant (even though in reality the resistance might increase markedly with current), find (a) the total power supplied by the power source and (b) the potential difference across each lightbulb.arrow_forwardWhen the current in the portion of the circuit shown in Figure P32.65 is 2.00 A anti increases at a rate of 0.500 A/s, the measured voltage is Vab = 9.00 V. When the current is 2.00 A and decreases at the rate of 0.500 A/s. the measured voltage is Vab = 5.00 V. Calculate the values of (a) I. and (b) Rarrow_forward
- Three 60.0-W, 120-V lightbulbs are connected across a 120-V power source, as shown in Figure P18.50. Find (a) the total power delivered to the three bulbs and (b) the potential difference across each. Assume the resistance of each bulb is constant (even though, in reality, the resistance increases markedly with current). Figure P18.50arrow_forwardWhen a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T T0)] (Eq. 17.7), where is the temperature coefficient of resistivity. (a) Show that a more precise result, which includes the length and area of a wire change when it is heated, is R=R0[1+(TT0)][1+(TT0)][1+2(TT0)] where is the coefficient of linear expansion. (See Topic 10.) (b) Compare the two results for a 2.00-m-long copper wire of radius 0.100 mm, starting at 20.0C and heated to 100.0C.arrow_forwardWhen a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T T0)] (Eq. 17.7), where is the temperature coefficient of resistivity. (a) Show that a more precise result, which includes the length and area of a wire change when it is heated, is R=R0[1+(TT0)][1+(TT0)][1+2(TT0)] where is the coefficient of linear expansion. (See Topic 10.) (b) Compare the two results for a 2.00-m-long copper wire of radius 0.100 mm, starting at 20.0C and heated to 100.0C.arrow_forward
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College