Dynamic Electricity - Review

A device designed to open or close a circuit under controlled conditions is called a variable resistor.

• TRUE

• FALSE

Current in a series circuit is different in different locations.

• TRUE

• FALSE

What is this symbol for?

• light bulb

• switch

• battery

• resistor

What size resistor would produce a 3 Amp current flow with a 12 Volt battery?

• 4 A

• 4 Ω

• 36 A

• 36 Ω

A student made an electric circuit. The student has made a mistake in this circuit. What is the mistake ?

• too many batteries in the circuit

• batteries connected in wrong position

• ammeter connected in parallel with lamps

• ammeter connected in series with lamps

When one bulb burns out ....

• the other bulbs burn brighter.

• nothing changes in the rest of the circuit.

• none of the other bulbs will light up.

• the other bulbs burn dimmer.

What will happen if one light bulb is removed from this circuit?

• The other bulbs will go out.

• The other bulbs will get dimmer.

• The battery will become stronger.

• The other bulbs will get brighter.

Two resistances, one 10 Ω and the other 20 Ω, are connected in parallel. What is the equivalent resistance of the parallel combination?

• 3.33 Ω

• 6.7 Ω

• 7.7 Ω

• 30 Ω

In the circuit below there are four identical light bulbs A - D and also a resistor R. All the lamps in the circuit are lit. Which lamp shines brightest?

• lamp A

• lamp B

• lamp C

• lamp D

In the circuit below there are four identical light bulbs A - D and also a resistor R. All the lamps in the circuit are lit. Which lamp shines weakest?

• lamp A

• lamp B

• lamp C

• lamp D