Question 1

At what rate is thermal energy generated in the 30-$\Omega$resistor?

Accepted Answer

A) 20 W 
B) 27 W 
C) 60 W 
D) 13 W 
E) 30 W 
A) 20 W 
B) 27 W 
C) 60 W 
D) 13 W 
E) 30 W

Question 2

In a loop in a closed circuit,the sum of the currents entering a junction equals the sum of the currents leaving a junction because

Accepted Answer

A) the potential of the nearest battery is the potential at the junction. 
B) there are no transformations of energy from one type to another in a circuit loop. 
C) capacitors tend to maintain current through them at a constant value. 
D) current is used up after it leaves a junction. 
E) charge is neither created nor destroyed at a junction. 
A) the potential of the nearest battery is the potential at the junction. 
B) there are no transformations of energy from one type to another in a circuit loop. 
C) capacitors tend to maintain current through them at a constant value. 
D) current is used up after it leaves a junction. 
E) charge is neither created nor destroyed at a junction.

Question 3

An electric heater is constructed by applying a potential difference of 110 V across a wire with a resistance of 5.0 $\Omega$.What is the power rating of the heater?

Accepted Answer

A) 2.0 kW 
B) 2.4 kW 
C) 1.7 kW 
D) 1.5 kW 
E) 60 kW 
A) 2.0 kW 
B) 2.4 kW 
C) 1.7 kW 
D) 1.5 kW 
E) 60 kW

Question 4

If I = 0.40 A in the circuit segment shown below,what is the potential difference Va -Vb?

Accepted Answer

A) 31 V 
B) 28 V 
C) 25 V 
D) 34 V 
E) 10 V 
A) 31 V 
B) 28 V 
C) 25 V 
D) 34 V 
E) 10 V

Question 5

Which two circuits are exactly equivalent?

Accepted Answer

A) A and B 
B) B and C 
C) C and D 
D) D and E 
E) B and E 
A) A and B 
B) B and C 
C) C and D 
D) D and E 
E) B and E

Question 6

If R1 = 10 $\Omega$,R2 = 15$\Omega$,R3 = 20 $\Omega$,and I = 0.50 A,at what rate is heat being generated in these resistors?

Accepted Answer

A) 29 W 
B) 16 W 
C) 22 W 
D) 11 W 
E) 1.1 W 
A) 29 W 
B) 16 W 
C) 22 W 
D) 11 W 
E) 1.1 W

Question 7

What is the equivalent resistance between points A and B in the figure when R = 10 $\Omega$?

Accepted Answer

A) 20 $\Omega$ 
B) 10 $\Omega$ 
C) 25 $\Omega$ 
D) 15 $\Omega$ 
E) 3.2 $\Omega$ 
A) 20 $\Omega$ 
B) 10 $\Omega$ 
C) 25 $\Omega$ 
D) 15 $\Omega$ 
E) 3.2 $\Omega$

Question 8

A battery has an internal resistance of 4.0  $\Omega$ .Which of the following load resistors would have the most power delivered to it when connected across the battery?

Accepted Answer

A) 1.4  $\Omega$ 
B) 2.0 $\Omega$ 
C) 4.0 $\Omega$ 
D) 8.0 $\Omega$ 
E) 16  $\Omega$ 
A) 1.4  $\Omega$ 
B) 2.0 $\Omega$ 
C) 4.0 $\Omega$ 
D) 8.0 $\Omega$ 
E) 16  $\Omega$

Question 9

A capacitor in a single-loop RC circuit is charged to 85% of its final potential difference in 2.4 s.What is the time constant for this circuit?

Accepted Answer

A) 1.5 s 
B) 1.3 s 
C) 1.7 s 
D) 1.9 s 
E) 2.9 s 
A) 1.5 s 
B) 1.3 s 
C) 1.7 s 
D) 1.9 s 
E) 2.9 s

Question 10

If$\varepsilon$ = 8.0 V,at what rate is that emf providing energy to the circuit shown below?

Accepted Answer

A) 8.4 W 
B) 7.6 W 
C) 5.6 W 
D) 11 W 
E) 2.0 W 
A) 8.4 W 
B) 7.6 W 
C) 5.6 W 
D) 11 W 
E) 2.0 W

Question 11

In the Drude model of electrical conduction,the current density is directly proportional to

Accepted Answer

A) the average time interval between successive collisions. 
B) the number of charge carriers per unit volume. 
C) the square of the electron charge. 
D) the electric field present in the wire. 
E) the product of all four quantities listed above. 
A) the average time interval between successive collisions. 
B) the number of charge carriers per unit volume. 
C) the square of the electron charge. 
D) the electric field present in the wire. 
E) the product of all four quantities listed above.

Question 12

How many electrons pass through a 20-$\Omega$ resistor in 10 min if there is a potential drop of 30 volts across it?

Accepted Answer

A) 5.6*1021 
B) 7.5 *1021 
C) 9.4 * 1021 
D) 1.1* 1021 
E) 3.8* 1021 
A) 5.6*1021 
B) 7.5 *1021 
C) 9.4 * 1021 
D) 1.1* 1021 
E) 3.8* 1021

Question 13

An electric device,which heats water by immersing a resistance wire in the water,generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads.What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)

Accepted Answer

A) 0.94 $\Omega$ 
B) 0.81 $\Omega$ 
C) 0.58 $\Omega$ 
D) 0.69 $\Omega$ 
E) 1.5$\Omega$ 
A) 0.94 $\Omega$ 
B) 0.81 $\Omega$ 
C) 0.58 $\Omega$ 
D) 0.69 $\Omega$ 
E) 1.5$\Omega$

Exam 21: Current and Direct Current Circuits

At what rate is thermal energy generated in the 30- Ω\OmegaΩ resistor?

In a loop in a closed circuit,the sum of the currents entering a junction equals the sum of the currents leaving a junction because

An electric heater is constructed by applying a potential difference of 110 V across a wire with a resistance of 5.0 Ω\OmegaΩ .What is the power rating of the heater?

If I = 0.40 A in the circuit segment shown below,what is the potential difference Va -Vb?

Which two circuits are exactly equivalent?

If R1 = 10 Ω\OmegaΩ ,R2 = 15 Ω\OmegaΩ ,R3 = 20 Ω\OmegaΩ ,and I = 0.50 A,at what rate is heat being generated in these resistors?

What is the equivalent resistance between points A and B in the figure when R = 10 Ω\OmegaΩ ?

A battery has an internal resistance of 4.0 Ω\OmegaΩ .Which of the following load resistors would have the most power delivered to it when connected across the battery?

A capacitor in a single-loop RC circuit is charged to 85% of its final potential difference in 2.4 s.What is the time constant for this circuit?

If ε\varepsilonε = 8.0 V,at what rate is that emf providing energy to the circuit shown below?

In the Drude model of electrical conduction,the current density is directly proportional to

How many electrons pass through a 20- Ω\OmegaΩ resistor in 10 min if there is a potential drop of 30 volts across it?

An electric device,which heats water by immersing a resistance wire in the water,generates 50 cal of heat per second when an electric potential difference of 12 V is placed across its leads.What is the resistance of the heater wire? (Note: 1 cal = 4.186 J)

Introduction and Vectors

Motion in One Dimension

Motion in Two Dimensions

The Laws of Motion

More Applications of Newtons Laws

Energy of a System

Conservation of Energy

Momentum and Collisions

Relativity

Rotational Motion

Gravity,planetary Orbits,and the Hydrogen Atom

Oscillatory Motion

Mechanical Waves

Superposition and Standing Waves

Fluid Mechanics

Temperature and the Kinetic Theory of Gases

Energy in Thermal Processes: the First Law of Thermodynamics

Heat Engines,entropy,and the Second Law of Thermodynamics

Electric Forces and Electric Fields

Electric Potential and Capacitance

Magnetic Forces and Magnetic Fields

Faradays Law and Inductance

Electromagnetic Waves

Reflection and Refraction of Light

Image Formation by Mirrors and Lenses

Wave Optics

Quantum Physics

Atomic Physics

Nuclear Physics

Particle Physics

Filters

At what rate is thermal energy generated in the 30- $\Omega$ resistor? $At what rate is thermal energy generated in the 30- \Omega resistor?$

An electric heater is constructed by applying a potential difference of 110 V across a wire with a resistance of 5.0 $\Omega$ .What is the power rating of the heater?

If I = 0.40 A in the circuit segment shown below,what is the potential difference V_a -V_b?

If R₁ = 10 $\Omega$ ,R₂ = 15 $\Omega$ ,R₃ = 20 $\Omega$ ,and I = 0.50 A,at what rate is heat being generated in these resistors? $If R<sub>1</sub> = 10 \Omega ,R<sub>2</sub> = 15 \Omega ,R<sub>3</sub> = 20 \Omega ,and I = 0.50 A,at what rate is heat being generated in these resistors?$

What is the equivalent resistance between points A and B in the figure when R = 10 $\Omega$ ? $What is the equivalent resistance between points A and B in the figure when R = 10 \Omega ?$

A battery has an internal resistance of 4.0 $\Omega$ .Which of the following load resistors would have the most power delivered to it when connected across the battery?

If $\varepsilon$ = 8.0 V,at what rate is that emf providing energy to the circuit shown below? $If \varepsilon = 8.0 V,at what rate is that emf providing energy to the circuit shown below?$

How many electrons pass through a 20- $\Omega$ resistor in 10 min if there is a potential drop of 30 volts across it?