8th grade electricity and magnetism

Question 1

Series and parallel: which statement is NOT true?

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

Question 2

Two resistors of 11 Ω and 12 Ω are connected in series. What is their total resistance, in Ω?

Answer Ω

Question 3

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

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

Question 4

A 1.4 A current leaves a battery and splits into two parallel branches. One branch carries 0.2 A. What current flows in the other branch, in A?

Answer A

Question 5

A 0.75 V battery drives a current of 0.25 A through a lamp. What is the resistance of the lamp, in Ω?

Answer Ω

Question 6

How is an ammeter connected to measure the current through a lamp?

• A. it is not connected
• B. in parallel with the lamp
• C. across the battery only
• D. in series with the lamp

Question 7

A current of 3 A flows through a 20 Ω resistor. What is the potential difference (voltage) across it, in V?

Answer V

Question 8

A 12 V supply is connected across a 6 Ω resistor. What current flows, in A?

Answer A

Question 9

Two lamps are connected in series to a 9 V battery. The voltage across the first lamp is 6 V. What is the voltage across the second lamp, in V?

Answer V

Question 10

Series and parallel: which statement is NOT true?

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

Question 11

Two lamps are in series with a 12 V battery. The voltage across one lamp is 8 V. What is the voltage across the other lamp, in V?

Answer V

Question 12

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

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

Question 13

Two lamps are in parallel. The current through one branch is 0.5 A and through the other is 0.4 A. What current flows from the battery, in A?

Answer A

Question 14

A 48 V battery drives a current of 4 A through a lamp. What is the resistance of the lamp, in Ω?

Answer Ω

Question 15

In a series circuit, the current is…

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

Question 16

A current of 3 A flows through a 20 Ω resistor. What is the potential difference (voltage) across it, in V?

Answer V