What is another name for electromagnetic induction?
The motor effect
The generator effect
A solenoid
What type of current is induced when a magnet moves in and out of a coil?
D.C.
A.C.
U.V.
What is the name of the a.c. generator used in a car?
An indicator
A starter motor
An alternator
A coil of wire is connected to a sensitive centre-zero ammeter. A north pole of a magnet is moved towards the coil before coming to rest inside it. The needle of the ammeter initially deflects to the right. What happens next?
The needle of the ammeter remains deflected to the right
The needle of the ammeter deflects to the left of the centre zero
The needle of the ammeter returns to zero
How can the direction of an induced current be reversed?
By changing the direction of the magnetic field
By moving the magnet faster
By changing the direction of the magnetic field, and moving the magnet in the opposite direction
What is the voltage from an a.c. generator half a turn of the coil after maximum positive output?
Maximum negative output
Maximum positive output again
Zero voltage
How can the induced current output from an a.c. generator be increased?
Reverse the direction of rotation
Increase the speed of rotation
Halve the speed of rotation but also reverse the direction of rotation
What is the function of a microphone?
It converts alternating current signals into direct current signals
It converts electrical signals into sound waves
It converts sound waves into electrical signals
What is the frequency of mains voltage in the UK?
50 Hz
240 Hz
99.7 MHz
How many cycles of alternating current are induced when the coil of a generator makes one complete rotation?
½ cycle
1 cycle
2 cycles