Chapter 25 QUIZ

If the current through a resistor is increased by a factor of 4, how does

this affect the power that is dissipated?

• It decreases by a factor of 4

• It increases by a factor of 2

• It decreases by a factor of 8

• It increases by a factor of 16

You make a parallel connection between two resistors, resistor A

having a very small resistance and resistor B having a very large resistance.

The equivalent resistance for this combination will be

• slightly greater than the resistance of resistor A

• slightly less than the resistance of resistor A

• slightly greater than the resistance of resistor B

• slightly less than the resistance of resistor B

Two cylindrical wires, 1 and 2, made of the same material, have the

same resistance. If the length of wire 2 is three times that of wire 1, what is the

ratio of their cross-sectional areas, A₁ and A₂?

• A1/A2 = 3.33

• A1/A2 = 0.35

• A1/A2 = 0.33

• A1/A2 = 3.35

Which of the arrangements of three identical light bulbs shown in the figure draws the lowest current from the battery?

• A

• B

• C

• All three draw equal current

Which of the arrangements of three identical light bulbs shown in the

figure has the highest resistance?

• A

• B

• C

• All three have equal resistance

Three identical light bulbs are connected as shown in the figure. Initially the switch is closed. When the switch is opened (as shown in the figure), bulb C goes off. What happens to bulbs A and B?

• Both bulbs A and B get brighter.

• Bulb A gets brighter, and bulb B gets dimmer.

• Both bulbs A and B get dimmer.

• Bulb A gets dimmer, and bulb B gets brighter.

Ohm’s Law states that the potential difference across a device is equal to

• the current flowing through the device divided by the resistance of the device.

• the current flowing through the device times the cross-sectional area of the device.

• the current flowing through the device times the resistance of the device.

• the current flowing through the device times the length of the device.

Which of the following is an incorrect statement?

• The currents through electronic devices connected in series are equal.

• The potential drops across electronic devices connected in parallel are equal.

• More current flows across the smaller resistance when two resistors are

  connected in parallel.

• More current flows across the smaller resistance when two resistors are

  connected in series.

When a battery is connected to a lightbulb, current flows

through the lightbulb and makes it glow. How much current

flows through the battery compared with the lightbulb?

• More Current

• Less Current

• The Same Amount

• No current flows through the battery

The unit kilowatt-hour is a measure of

• the rate at which energy is transformed

• power

• an amount of energy

• the amount of power used per second