WorksheetsElectromagnetic Test
Total questions: 20
Worksheet time: 1hrs 25mins
Diagram 33 shows an electric motor. Which magnetic field pattern is correct when the switch is closed?
The diagram 34 below shows a wire QR hangs freely between two strong magnets. The angle of deflection, θ is increased by
increasing the current
changing the polarity of the magnet
increasing the resistance of the wire QR
increasing the distance between the poles of the magnet
The diagram below shows an electric generator. Which graph shows the correct output between voltage and time when the coil starts to rotate?
Diagram below shows the primary coil of a transformer is connected to a 240 V a.c. supply and an output voltage of 12 V is produced. What is the ratio of the number of turns in the secondary coil. NS to the number of turns in the primary coil, NP?
40 : 2
4 : 24
1 : 20
2 : 40
Diagram 37 below shows a system for the transmission of electricity. Which combination of transformers P and Q is correct?
P : Step down, Q: Step up
P: Step up, Q: Step down
P: Step up, Q: Step up
P: Step down, Q: Step down
Diagram shows a magnet bar moves toward a solenoid. What is the magnetic polarity at both end of solenoid?
X: South. Y: South
X: South, Y: North
X: North, Y: North
X: North, Y: South
The motion of current carrying conductor in magnetic field can be determined by
Direction of current flow
Fleming's right hand rule
Felming's left hand rule
Right hand grip rule
What happens to the galvanometer if the copper rod is moved upwards?
No change
Deflect to the right
Deflect to the left
Deflect to the right and left
Which action will increase the deflection of the galvanometer pointer?
The magnetic pole is reversed
The number of turns of coils is increased
The coil is made from insulated wire
The magnet is slowly pushed into the coil
What happen to the Galvanometer?
Deflected to the right
Deflected to the left
Nothing happen
National Grid Network consists of
Power stations - step-up transformers - transmission lines - step-down transformers - consumers
Power stations - transmission lines - step-up transformers - consumers - step-down transformers
Power stations - step-down transformers - transmission lines -step-up transformers - consumers
Power stations - step-up transformers - consumers - transmission lines - step-down transformers
Calculate the voltage for secondary circuit
12.5 V
25 V
50 V
100 V
Calculate the current that flows in secondary circuit
0.03 A
0.075 A
0.015 A
0.020 A
Direction of deflection of the galvanometer pointer can be determined by
Lenz's Law
Faraday's Law
Fleming's Left Hand Rule
Fleming's Right Hand Rule
Based on the picture in red box,
Why the Galvanometer pointer is at the middle?
Current flow through wire
There is change in magnetic flux
No change in magnetic flux
