Answer for Combined Science Physics (Practical Electricity, Magnestism, Electromagnetis) Common Test

Dear Combined Science Physics students,

As per request, below is the answer to your Practical Electricity, Magnetism & Electromagnetism CA test. All the best for your Major Test tomorrow! I am proud of your hardwork! :)

Section A MCQ
1. C 10. B
2. B 11. C
3. D 12. C
4. B 13. D
5. B 14. A
6. B 15. D
7. B 16. B
8. A 17. A
9. B 18. D

Section B Short Questions
1a.











1b.

600 W = 0.6 kW [1M]

E = 0.6 x 5

= 3kWh [1M]

2a.

Diagram -1M

1. Set up the experiment as shown in the diagram. [1/2 M]

2. Insert the steel bar into the solenoid. [1/2 M]

3. Conncect the solenoid to DC (Direct Current) Supply. [1M]

4. The steel will be magnetised.

2b.

Iron can be easily magnetised and easily demagnetised. [1M]

Steel is difficult to magnetised and difficult to demagnetised. [1M]

Steel is not used as a core of a circuit breaker because it cannot

be demagnetised easily when the current changes direction of switched off. [1M]

3a. When S is closed, both metal rods are magnetized with the same polarity. [1M]

Therefore the 2 metal rods repel each other since like poles repel. [1M]

3b. The iron rod becomes demagnetized [1M] while the steel rod remains magnetized.
[1M]. The steel rod induces magnetism in the iron rod therefore due to the
attractive forces between the rods, the rods move towards each other. [1M]

3c.
The rod that attracts the pins is STEEL. [1] Because steel retains its magnetism while iron loses its magnetism[1]

4a

1 ting is heard. [1M] When the circuit is closed, current flows through the solenoid [1/2M] and it becomes an electromagnet. [1/2M] Hence, the electromagnet attracts the soft iron towards it [1/2M] and caused the hammer to strike gong 1 [1/2M]

4b. The hammer will hit gong 1 faster and louder. [1/2]. When the circuit is closed,
more current flows through the solenoid [1/2M] and it magnetized the iron faster. [1/2M]. Hence, the electromagnet attracts the soft iron towards it and caused the hammer to strike gong 1 once faster. [1/2M]

5. [Refer to notes]

[1M – for drawing attraction field lines]

[1M – for drawing the rest of field lines]

[-1/2 M for wrong direction]

[-1/2 M for overlapping field lines]

6ai. Upwards [1M]

aii. According to Fleming’s Left Hand Rule, [1M] the force exerted on the wire is perpendicular [1/2M] to the direction of magnetic field and direction of current. [1/2M]

aiii. By Fleming’s Left Hand Rule, [1M] the side AB will move downwards. [1M]