Question
Four wires are made from the same metal.
Which wire has the lowest resistance?
| length of wire / cm | diameter of wire / mm |
A | 20 | 0.20 |
B | 20 | 0.40 |
C | 40 | 0.20 |
D | 40 | 0.40 |
Answer/Explanation
Ans: A
Question
A student uses the circuit shown to determine the resistance of two identical resistors.
The voltmeter reading is 2.2 V and the ammeter reading is 0.25 A. What is the resistance of each resistor?
A 0.275 
B 0.55
C 4.4
D 8.8
Answer/Explanation
Ans: C
Question
A student measures the potential difference across a device and the current in the device.
Which calculation gives the resistance of the device?
A current + potential difference
B current ÷potential difference
C potential difference ÷ current
D potential difference× current
Answer/Explanation
Ans: C