Current and voltage KS3

Electrons exist throughout the wire even when current is not flowing.

• true

• false

• not sure

Current is...

• ...measured in volts with an voltmeter

• ...measured in volts with an ammeter

• ...measured in Amps with an voltmeter

• ...measured in Amps with an ammeter

Which answer best describes the voltage of a battery?

• how long it will last for

• how strongly it can push the current

• how fast the current will be

• how large the battery is

What is the ammeter measuring?

• the size of the current flowing through the bulb

• the brightness of the bulb

• the voltage of the battery

• the size of the current that the bulb uses up

Which is the correct description of how current flows in a circuit?

• 
• 
• 
• 

A very long circuit is set up that goes around the whole science lab.

What happens when the switch is turned on and why?

• the bulb turns on after a second as the current takes time to reach the bulb

• the bulb turns on after a split second as the current travels quickly to the bulb

• the bulb turns on instantaneously as the electrons all start moving at the same time

• I'm not really sure

A motor is added to this circuit.

What happens and why?

• Both ammeter readings stay the same because the batteries are pushing just as hard.

• Both ammeter readings go down together because the motor slows down the current everywhere in the circuit by the same amount.

• Both ammeter readings go down but ammeter 1 is still higher than ammeter 2 because the motor uses up some current, the bulb uses up a bit too.

• Ammeter 1 goes down more because the motor slows down the current more on the left.

Which bulb will be the brightest and why?

• A because it is designed for torches

• B because it has the most electricity in it

• C because it has the largest voltage so it pushes the biggest current

• they are all the same because the bulbs are the same

A circuit consists of 2 batteries and a bulb.

The bulb is lit very brightly.

What will happen to the brightness of the bulb and why?

• the bulb gets brighter because there is less resistance

• the bulb gets dimmer because there is a lower voltage, so it pushes a smaller current round

• the bulb gets dimmer because there is less energy than before

A 3V battery is added to a circuit with a 1.5V as shown in the diagram.

What happens to the bulb?

• it is lit brighter than before as the voltage is now 4.5V

• it is not lit because the bulb is connected to both positive terminals

• it is the same as before because the batteries cancel out and the new voltage is 1.5V

• it is not lit because current cannot go the wrong way through a battery