Kirchoff's Rules and Circuits

Assume that the voltage of the battery is 9 V and that the three resistors are identical. What is the potential difference across each resistor?

• 12 V

• 0 V

• 3 V

• 4 V

In the circuit below, what is the voltage across R1?

• 12 V

• 6 V

• 8 V

• 4 V

What is the current through R1?

• 10 A

• 5 A

• 7 A

• 2 A

Points P and Q are connected to a battery of fixed voltage. As more resistors R are added to the parallel circuit, what happens to the total current in the circuit?

• increases

• remains the same

• decreases

• drops to zero

Current flows through a lightbulb. If a wire is now connected across the bulb, what happens?

• all the current continues to flow through the bulb

• half the current flows through the wire, the other half continues through the bulb

• all the current flows through the wire

• none of the above

Two lightbulbs A and B are connected in series to a constant voltage source. When a wire is connected across B, bulb A will:

• glow brighter than before

• glow just the same as before

• glow dimmer than before

• go out completely

The lightbulbs in the circuit below are identical with the same resistance R. Which circuit produces more light? (brightness ÜÞ power)

• circuit 1

• circuit 2

• both the same

• it depends on R

The three lightbulbs in the circuit all have the same resistance of 1 W . By how much is the brightness of bulb B greater or smaller than the brightness of bulb A? (brightness <=> power)

• twice as much

• 1/2 as much

• 1/4 as much

• 4 times as much

What happens to the voltage across the resistor R1 when the switch is closed? The voltage will:

• increases

• decreases

• remains the same

What happens to the voltage across the resistor R4 when the switch is closed?

• increases

• decreases

• stays the same