Question 1

A 2.0-μF capacitor and a 4.0-μF capacitor are connected in series across an 8.0-V potential source.What is the charge on the 2.0-μF capacitor?

Accepted Answer

A) 2.0 μC 
B) 4.0 μC 
C) 12 μC 
D) 11 μC 
E) 25 μC 
A) 2.0 μC 
B) 4.0 μC 
C) 12 μC 
D) 11 μC 
E) 25 μC

Question 2

A 4.0-Ω resistor is connected with a 12-Ω resistor and this combination is connected across an ideal dc power supply with V = 6.0 V,as shown in the figure.When a total current I flows from the power supply,what is the current through the 12-Ω resistor?

Accepted Answer

A) 1.5 A 
B) 2.0 A 
C) 2.5 A 
D) 3.0 A 
E) 0.50 A 
A) 1.5 A 
B) 2.0 A 
C) 2.5 A 
D) 3.0 A 
E) 0.50 A

Question 3

A 200-Ω resistor is rated at 1/4 W.What is the maximum voltage that can safely be connected across it?

Accepted Answer

A) 0.71 V 
B) 7.1 V 
C) 50 V 
D) 0.25 V 
A) 0.71 V 
B) 7.1 V 
C) 50 V 
D) 0.25 V

Question 4

In the circuit shown in the figure,the resistor R has a variable resistance.As R is decreased,what happens to the currents?

Accepted Answer

A) I1 remains unchanged and I2 increases. 
B) I1 decreases and I2 decreases. 
C) I1 decreases and I2 increases. 
D) I1 increases and I2 decreases. 
E) I1 increases and I2 increases. 
A) I1 remains unchanged and I2 increases. 
B) I1 decreases and I2 decreases. 
C) I1 decreases and I2 increases. 
D) I1 increases and I2 decreases. 
E) I1 increases and I2 increases.

Question 5

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor.If you want to achieve the largest possible resistance,you should attach the leads to the opposite faces that measure

Accepted Answer

A) 3 cm × 5 cm. 
B) 3 cm × 8 cm. 
C) 5 cm × 8 cm. 
D) Any pair of faces produces the same resistance. 
A) 3 cm × 5 cm. 
B) 3 cm × 8 cm. 
C) 5 cm × 8 cm. 
D) Any pair of faces produces the same resistance.

Question 6

A certain 20-A circuit breaker trips when the current in it equals 20 A.What is the maximum number of 100-W light bulbs you can connect in parallel in an ideal 120-V dc circuit without tripping this circuit breaker?

Accepted Answer

A) 11 
B) 17 
C) 23 
D) 27 
A) 11 
B) 17 
C) 23 
D) 27

Question 7

A multiloop circuit is shown in the figure.Find the emf ε1 if the batteries are ideal.(It is not necessary to solve the entire circuit. )

Accepted Answer

A) -4 V 
B) 4 V 
C) 44 V 
D) 52 V 
E) -52 V 
A) -4 V 
B) 4 V 
C) 44 V 
D) 52 V 
E) -52 V

Question 8

A resistor,an uncharged capacitor,a dc voltage source,and an open switch are all connected in series.The switch is closed at time t = 0 s.Which one of the following is a correct statement about this circuit?

Accepted Answer

A) The charge on the capacitor after four time constants is about 98% of the maximum value. 
B) The charge on the capacitor after one time constant is 50% of its maximum value. 
C) The charge on the capacitor after one time constant is 1/e of its maximum value. 
D) The voltage on the capacitor after one time constant is 1/e of the maximum value. 
E) The voltage on this capacitor after one time constant is 100% of its maximum value. 
A) The charge on the capacitor after four time constants is about 98% of the maximum value. 
B) The charge on the capacitor after one time constant is 50% of its maximum value. 
C) The charge on the capacitor after one time constant is 1/e of its maximum value. 
D) The voltage on the capacitor after one time constant is 1/e of the maximum value. 
E) The voltage on this capacitor after one time constant is 100% of its maximum value.

Question 9

Which one of the following quantities is equivalent to 1 W?

Accepted Answer

A) 1 V/A 
B) 1 Ω ∙ m 
C) 1 V ∙ A 
D) 1 V/Ω 
E) 1 A ∙ s 
A) 1 V/A 
B) 1 Ω ∙ m 
C) 1 V ∙ A 
D) 1 V/Ω 
E) 1 A ∙ s

Question 10

The resistivity of gold is  
At a temperature of 20°C.A gold wire,1.8 mm in diameter and 14 cm long,carries a current of 480 mA.What power is dissipated in this wire at 20°C?

Accepted Answer

A) 0.31 mW 
B) 0.077 mW 
C) 0.14 mW 
D) 0.19 mW 
E) 0.25 mW 
A) 0.31 mW 
B) 0.077 mW 
C) 0.14 mW 
D) 0.19 mW 
E) 0.25 mW

Question 11

The resistivity of a 1.0 m long copper wire is 1.72 × 10-8 Ω ∙ m and its cross sectional area is 2.0 × 10-6 m2.If the wire carries a current of 0.20 A,what is the voltage across the wire?

Accepted Answer

A) 17 mV 
B) 0.90 mV 
C) 1.7 mV 
D) 10 mV 
E) 90 mV 
A) 17 mV 
B) 0.90 mV 
C) 1.7 mV 
D) 10 mV 
E) 90 mV

Question 12

Which one of the following quantities is equivalent to 1 Ω?

Accepted Answer

A) 1 J/s 
B) 1 W/A 
C) 1 V ∙ A 
D) 1 V/A 
E) 1 A ∙ s 
A) 1 J/s 
B) 1 W/A 
C) 1 V ∙ A 
D) 1 V/A 
E) 1 A ∙ s

Question 13

A network of capacitors is mostly inside a sealed box,but one capacitor CX is sticking out,as shown in the figure.When you connect a multimeter across points a and b,it reads 27.0 µF.What is CX?

Accepted Answer

A) 27.0 µF 
B) 23.0 µF 
C) 4.0 µF 
D) 2.4 µF 
E) 2.2 µF 
A) 27.0 µF 
B) 23.0 µF 
C) 4.0 µF 
D) 2.4 µF 
E) 2.2 µF

Question 14

A potential difference of V = 100 V is applied across two capacitors in series,as shown in the figure.If  
=  
And the voltage drop across it is 75 V,what is the capacitance of C2?

Accepted Answer

A) 30 μF 
B) 2.5 μF 
C) 7.5 μF 
D) 3.3 μF 
A) 30 μF 
B) 2.5 μF 
C) 7.5 μF 
D) 3.3 μF

Question 15

What potential difference is required to cause 4.00 A to flow through a resistance of 330 Ω?

Accepted Answer

A) 12.1 V 
B) 82.5 V 
C) 334 V 
D) 1320 V 
A) 12.1 V 
B) 82.5 V 
C) 334 V 
D) 1320 V

Question 16

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Accepted Answer

A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity) 
A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity)

Question 17

If emf of the ideal battery is V = 4.0 V,what is the current through R6 for the circuit shown in the figure?

Accepted Answer

A) 0.0077 A 
B) 0.017 A 
C) 0.040 A 
D) 4.0 A 
A) 0.0077 A 
B) 0.017 A 
C) 0.040 A 
D) 4.0 A

Question 18

Identical light bulbs can be attached to identical ideal batteries in three different ways (A,B,orC),as shown in the figure.The ranking (from lowest to highest)of the total power produced by the battery is

Accepted Answer

A) B,A,C. 
B) A,B,C. 
C) C,B,A. 
D) A,C,B. 
A) B,A,C. 
B) A,B,C. 
C) C,B,A. 
D) A,C,B.

Question 19

In an electroplating process,it is desired to deposit 40 mg of silver on a metal part by using a current of 2.0 A.How long must the current be allowed to run to deposit this much silver? The silver ions are singly charged,and the atomic mass of silver is 108 g/mol.(e = 1.60 × 10-19 C,NA = 6.02 × 1023 atoms/mol)

Accepted Answer

A) 16 s 
B) 18 s 
C) 20 s 
D) 22 s 
A) 16 s 
B) 18 s 
C) 20 s 
D) 22 s

Question 20

The network shown is assembled with uncharged capacitors X ,Y,and Z,with  
 
And  
The switches S1 and S2 are initially open,and a potential difference Vab = 120 V is applied between points a and b.After the network is assembled,switch S1 is then closed,but switch S2 is kept open.How much charge is finally stored in capacitor Y?

Accepted Answer

A) 110 µC 
B) 54 µC 
C) 81 µC 
D) 140 µC 
E) 160 µC 
A) 110 µC 
B) 54 µC 
C) 81 µC 
D) 140 µC 
E) 160 µC

Exam 21: Electric Current and Direct-Current Circuits

A 2.0-μF capacitor and a 4.0-μF capacitor are connected in series across an 8.0-V potential source.What is the charge on the 2.0-μF capacitor?

A 4.0-Ω resistor is connected with a 12-Ω resistor and this combination is connected across an ideal dc power supply with V = 6.0 V,as shown in the figure.When a total current I flows from the power supply,what is the current through the 12-Ω resistor?

A 200-Ω resistor is rated at 1/4 W.What is the maximum voltage that can safely be connected across it?

In the circuit shown in the figure,the resistor R has a variable resistance.As R is decreased,what happens to the currents?

You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor.If you want to achieve the largest possible resistance,you should attach the leads to the opposite faces that measure

A certain 20-A circuit breaker trips when the current in it equals 20 A.What is the maximum number of 100-W light bulbs you can connect in parallel in an ideal 120-V dc circuit without tripping this circuit breaker?

A multiloop circuit is shown in the figure.Find the emf ε1 if the batteries are ideal.(It is not necessary to solve the entire circuit. )

A resistor,an uncharged capacitor,a dc voltage source,and an open switch are all connected in series.The switch is closed at time t = 0 s.Which one of the following is a correct statement about this circuit?

Which one of the following quantities is equivalent to 1 W?

The resistivity of gold is At a temperature of 20°C.A gold wire,1.8 mm in diameter and 14 cm long,carries a current of 480 mA.What power is dissipated in this wire at 20°C?

The resistivity of a 1.0 m long copper wire is 1.72 × 10-8 Ω ∙ m and its cross sectional area is 2.0 × 10-6 m2.If the wire carries a current of 0.20 A,what is the voltage across the wire?

Which one of the following quantities is equivalent to 1 Ω?

A network of capacitors is mostly inside a sealed box,but one capacitor CX is sticking out,as shown in the figure.When you connect a multimeter across points a and b,it reads 27.0 µF.What is CX?

A potential difference of V = 100 V is applied across two capacitors in series,as shown in the figure.If = And the voltage drop across it is 75 V,what is the capacitance of C2?

What potential difference is required to cause 4.00 A to flow through a resistance of 330 Ω?

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

If emf of the ideal battery is V = 4.0 V,what is the current through R6 for the circuit shown in the figure?

Identical light bulbs can be attached to identical ideal batteries in three different ways (A,B,orC),as shown in the figure.The ranking (from lowest to highest)of the total power produced by the battery is

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Gravity

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric

Magnetism

Magnetic Flux and Faradays Law of Induction

Alternating-Current Circuits

Electromagnetic Waves

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

A multiloop circuit is shown in the figure.Find the emf ε₁ if the batteries are ideal.(It is not necessary to solve the entire circuit. )

The resistivity of a 1.0 m long copper wire is 1.72 × 10^-8 Ω ∙ m and its cross sectional area is 2.0 × 10^-6 m².If the wire carries a current of 0.20 A,what is the voltage across the wire?

A network of capacitors is mostly inside a sealed box,but one capacitor C_X is sticking out,as shown in the figure.When you connect a multimeter across points a and b,it reads 27.0 µF.What is C_X?

A potential difference of V = 100 V is applied across two capacitors in series,as shown in the figure.If = And the voltage drop across it is 75 V,what is the capacitance of C₂?

If emf of the ideal battery is V = 4.0 V,what is the current through R₆ for the circuit shown in the figure?