Question 1

A battery with emf $$V_0$$ and internal resistance $$r is $$connected to a resistor $$R. $$Which equation correctly gives the current $$I in $$the circuit?

Accepted Answer

$$I = \frac{V_0$}{R + r}$$

Question 2

Which of the following best describes the function of the internal resistance $$r in a $$real battery?

Accepted Answer

It decreases the total current supplied to the external circuit.

Question 3

A 60 W light bulb is connected to a 120 V power supply. What is the resistance of the bulb?

Accepted Answer

$$R = \frac{V^2$}{P}$$

Question 4

If two resistors, $$R_1 = 2$$\ \Omega$$ and R_2$ = 4\ \Omega$$, are connected in series, what is the equivalent resistance?

Accepted Answer

$$R_{eq} = 6\ \Omega$$

Question 5

If the same resistors ($$R_1 = 2$$\ \Omega$$, R_2$ = 4\ \Omega) $$are connected in parallel, what is the equivalent resistance?

Accepted Answer

$$R_{eq} = 1.33\ \Omega$$

Question 6

A battery with emf $$V_0 = 12$$\ V$$ and internal resistance r = 1$$\ \Omega$$ is connected to a 5$$\ \Omega$$ resistor. What is the terminal voltage across the battery?

Accepted Answer

$$V = 12\ V - I r$$

Question 7

Which equation correctly expresses the electric power $$P$$ dissipated in a resistor $$R$$ with current $$I$$ flowing through it?

Accepted Answer

$$P = I^2$ R$$

Question 8

A household circuit is protected by a 15 A fuse. If the household voltage is 120 V, what is the maximum power that can be drawn before the fuse blows?

Accepted Answer

$$P = 1800\ W$$

Question 9

A student connects three identical light bulbs in parallel to a battery. If one bulb burns out, what happens to the brightness of the remaining bulbs?

Accepted Answer

The brightness of the remaining bulbs stays the same.

Question 10

Which of the following statements about series and parallel resistor circuits is correct?

Accepted Answer

In a series circuit, the current through each resistor is the same.

Question 11

A 100 W light bulb and a 60 W light bulb are connected in series to a 120 V supply. Which bulb will be brighter?

Accepted Answer

The 60 W bulb

Question 12

A device is rated at 240 V, 1000 W. What current does it draw when operated at its rated voltage?

Accepted Answer

$$I = 4.17\ A$$

Question 13

If the resistance in a circuit is doubled while the voltage remains constant, what happens to the power dissipated?

Accepted Answer

It is reduced to one-fourth

Question 14

A battery with emf $$V_0$$ and internal resistance $$r is $$short-circuited (connected directly with a wire of negligible resistance). What is the current?

Accepted Answer

$$I = \frac{V_0$}{r}$$

Question 15

Which of the following best explains why household appliances are connected in parallel rather than in series?

Accepted Answer

To ensure each appliance receives the same voltage

Question 16

A 12 V battery with internal resistance $$0.5\ \Omega is $$connected to a $$5.5\ \Omega$$ load. What is the power delivered to the load?

Accepted Answer

$$P = 21.8\ W$$

Electric Power and Resistor Circuits: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards