Welcome to your Grade 12 Physics chapter 4
After carefully reading the following 30 questions, choose the correct answer.
1.
Which device is used to change the voltage of an alternating current in an electrical circuit?
2.
What is the primary source of magnetism in a permanent magnet?
3.
According to Faraday's Law, what happens when there is a change in the magnetic flux through a conductor?
4.
What do magnetic field lines represent in a magnetic field?
5.
In an electromagnetic induction process, what is the effect of increasing the speed of relative motion between a magnet and a coil?
6.
Which rule is used to determine the direction of the magnetic field around a straight current-carrying wire?
7.
What is the purpose of the iron core in a transformer?
8.
A step-up transformer is designed to do what to the output voltage compared to the input?
9.
Which phenomenon is the basis for the operation of an electric generator?
10.
What defines the safety practice of "earthing" in electrical systems?
11.
In a magnetic field, where is the strength of the field strongest?
12.
What happens to the magnetic field produced by a solenoid if the number of turns in the coil is increased?
13.
Which material is commonly used to make the core of an electromagnet?
14.
What is the characteristic of magnetic field lines outside a bar magnet?
15.
What is induced in a secondary coil of a transformer when a varying current flows through the primary coil?
16.
Which factor does NOT affect the magnitude of the induced EMF in a coil?
17.
How do two like magnetic poles interact when brought close together?
18.
What is the function of a fuse in an electrical circuit?
19.
In electromagnetism, what is a solenoid?
20.
Which law is used to determine the polarity of an induced EMF?
21.
What is the main difference between a hard magnetic material and a soft magnetic material?
22.
What happens if a bar magnet is broken in half?
23.
Which device converts mechanical energy into electrical energy?
24.
What is mutual induction?
25.
What is the unit of magnetic flux?
26.
What effect does an alternating current have when flowing through a primary coil of a transformer?
27.
Which material is an example of a diamagnetic substance?
28.
What is the purpose of an circuit breaker?
29.
In the transformer equation, what is the relationship between voltage and the number of turns?
30.
What is the effect of placing a dielectric in a magnetic field?
