WorksheetsElectromagnetic Induction
Total questions: 13
Worksheet time: 1hrs 5mins
A bar magnet falling through a loop with the north pole facing down induces a current
in a clockwise direction
in an anticlockwise direction
first in a clockwise, then in an anticlockwise direction
first in an anticlockwise, then in a clockwise direction
Coil B lies in the same plane as coil A. If the switch is closed which direction will current flow in coil B?
Clockwise
Anticlockwise
No current will flow
A current will only flow if coil B is turned perpendicular to coil A
Magnetic flux density has the units:
Wb m–2
Wb A–1 m–1
T m–1
T m
A uniform magnetic field threads a circular loop with area A at angle θ . The strength of the field is increasing at a uniform rate R. What equation describes the EMF induced in the loop?
BAcosθ
RAsinθ
BILsinθ
RAcosθ
An ideal transformer has np primary turns, and ns secondary turns. The voltage across the primary is Vp. Determine the induced in the secondary, Vs.
nsnpVp
npnsVp
Vp nsnp
npnsVp
A transformer designed to step-down 240 V mains voltage to a voltage of 6 V AC. Calculate the number of turns on the secondary coil, given that the primary coil has 2000 turns.
20 turns
50 turns
150 turns
200 turns
A 200-turn coil with area 50 cm2 is placed perpendicular to a magnetic field as shown in the figure. The intensity of the field varies from 30 mT to 10 mT in a time of 0.02 s. Calculate the voltage on the coil.
0.1 V
1 V
100 V
107 V
Determine the direction of motion of the magnet when the current flows as shown.
towards the solenoid
away from the solenoid
standing still
moving back and forth
Determine the EMF induced in a coil that has 1200 evenly spaced turns and a radius of 2.5 cm, when a magnet is brought near its end so that the magnetic field inside it is increased from 0 to 0.060 T in 20 ms.
0.0032 V
1.52 V
7.06 V
9.86 V
An aircraft is flying through Earth’s magnetic field at a steady horizontal speed of 800 km/h. The vertical component of Earth’s magnetic field is 5.0 × 10–5 T. Determine the EMF generated between the wing tips if they are 25 m apart.
0.0
0.28 V
1 V
22.8 V
The solenoid to the right is moved as shown. Predict the effect (if any) on the solenoid to the left.
Current will flow from A to B through the voltmeter
Current will flow from B to A through the voltmeter
No current will flow
Current will flow from B to A through the solenoid
A transformer with 240V AC input and 50V AC output, has 400 turns on its primary coil. How many turns are on the secondary coil?
4.8 turns
54 turns
83 turns
1,920 turns
A transformer with 240V AC input and 50V AC output, has 400 turns on its primary coil. Is it a step down or a step up transformer
step-up
step-down
