The set up in the figure is used to study the relationship between current (I) and potential difference (V) for a wire X. The most likely shape of the graph of the potential difference (Y) against current (X) for the copper wire is:
A.
B.
C.
D.
The set up in the figure is used to study the relationship between current (I) and potential difference (V) for a wire X.
If the material X is a copper wire, the relationship between V and I when the switch is closed at constant temperature is:
Ohm’s law.
Hooke’s law.
Lenz’s law.
Coulomb’s law.
The ammeter is connected as shown because it has:
Very low resistance and so alters the current flowing through it.
Very low resistance and so does not alter the current flowing through it.
A very high resistance and so allows little current to flow through it.
Very high resistance and so allows high current to flow through it.
The rheostat Y is used to:
Vary electromotive force.
Vary the current in the circuit.
Keep the temperature constant.
Vary the resistance of the wire.
The heating element of an electric kettle has a resistance of 30.0 Ω.
The kettle is connected to an a.c. power supply of root means square voltage 230 V.
The peak value of the current is:
5.4 A.
15.2 A.
10.8 A.
7.7 A.
