8th grade electricity and magnetism

Question 1

In a series circuit, the current is…

• A. zero at the battery
• B. biggest after the bulb
• C. the same at every point
• D. used up by each component

Question 2

A 12 V supply is connected across a 8 Ω resistor. What current flows, in A?

Answer A

Question 3

In a parallel circuit with three lamps, one lamp breaks. What happens to the other two?

• A. they all go out
• B. they stay lit
• C. they flicker and stop
• D. they get dimmer

Question 4

A 2 V battery drives a current of 0.5 A through a lamp. What is the resistance of the lamp, in Ω?

Answer Ω

Question 5

Two lamps are connected in series to a 9 V battery. The voltage across the first lamp is 3 V. What is the voltage across the second lamp, in V?

Answer V

Question 6

Series and parallel: which statement is NOT true?

• A. Voltmeters are connected in parallel.
• B. Adding resistors in parallel increases the total resistance.
• C. In series, total resistance is the sum of the resistances.
• D. In a series circuit, if one bulb breaks, the others go out.

Question 7

A 2.2 A current leaves a battery and splits into two parallel branches. One branch carries 1 A. What current flows in the other branch, in A?

Answer A

Question 8

Two resistors of 3 Ω and 20 Ω are connected in series. What is their total resistance, in Ω?

Answer Ω

Question 9

A current of 4 A flows through a 10 Ω resistor. What is the potential difference (voltage) across it, in V?

Answer V

Question 10

Adding more bulbs in parallel to a battery (each in its own branch) makes each bulb…

• A. explode
• B. get much dimmer
• C. go out
• D. stay about as bright as before

Question 11

A 2.5 V supply is connected across a 5 Ω resistor. What current flows, in A?

Answer A

Question 12

Two identical lamps are connected in parallel to a 6 V battery. What is the voltage across each lamp?

• A. 6 V
• B. 3 V
• C. 0 V
• D. 12 V

Question 13

A 20 V battery drives a current of 4 A through a lamp. What is the resistance of the lamp, in Ω?

Answer Ω

Question 14

Two lamps are connected in series to a 12 V battery. The voltage across the first lamp is 6 V. What is the voltage across the second lamp, in V?

Answer V

Question 15

Series and parallel: which statement is NOT true?

• A. In a parallel circuit, the voltage across each branch is the same.
• B. In a series circuit, if one bulb breaks, the others go out.
• C. In series, total resistance is the sum of the resistances.
• D. Ammeters are connected in parallel.

Question 16

A 2.7 A current leaves a battery and splits into two parallel branches. One branch carries 1.5 A. What current flows in the other branch, in A?

Answer A