MCQs: Electric circuits
Three 6V batteries are connected as shown in the diagram.
Current will flow
Current flows from High potential to low.
A battery converts chemical energy to electrical energy.
Electrical energy is
Electrical PE is the energy electrons possess due top their position.
When electrons flow along a long wire
According to this animation the answer is C.
A copper wire has length 2m, cross sectional area 0.2mm2 and resitivity ρ. The resistance of the wire is
R= ρL/A = ρ x 2/0.2 x 10-6
If 4C of charge flows from P to S in the circuit shown how much energy would be lost?
PD = Energy/charge so energy = PD x charge = 6 x 4
In the following circuits a battery is connected to 4 different cylinders of copper.
The circuit with the largest current is
D has the shortest length and largest so smallest resistance Area R = ρL/A hence largest current
If the resistors in the circuit below are identical which ammeter will show the Lowest reading?
A and D are equal and will measure the total current going round the circuit.
There is more resistance in the top branch of the circuit so the current through B will be less than C.
The following circuits contain batteries and resistors that are identical. The current I flowing from the batteries is labelled.
In which circuit is I the biggest?
C has the least resistance and most PD.
A charge of 10C flows through a wire in 2 seconds. The current flowing is
I = Q/t
A current of 16A flows for 100s. The number of electrons that pass through the wire is
Q= It = 1600C
Number of electrons = charge / charge of electron = 1600/1.6 x 10-19 = 1022