Power Generator

Q.

What is the reason behind the use of electromagnets instead of permanent magnets in power generators.

1. The permanent magnets become shiny with time.

2. The strength of permanent magnet increases with time.

3. The shape of permanent magnets is huge.

4. The strength of permanent magnet decreases with time.

Q.

What is the frequency of alternating current (AC) generated for distribution in India?

1. 100 Hz

2. 500 Hz

3. 1000 Hz

4. 50 Hz

Q.

What is the speciality of a power generator?

1. Power generator converts only chemical energy into electrical energy.

2. Power generator converts any type of energy into electrical energy.

3. Power generator converts electrical energy into chemical energy.

4. Power generator converts electrical energy into mechanical energy.

Q.

Which one of the following is a type of power generator?

1. Dynamo

2. Ammeter

3. DC motor

4. Voltmeter

Q.

Power generators are used in the centres where large quantities of electricity is generated and is distributed.

1. True

2. False

Q. If the ends of a wire loop are attached to two half-circular metal strips, arranged so that the two strips almost form a complete circle, and those strips are contacted by two "brushes" which connect to opposite poles of a battery, what polarity of voltage will be measured as the loop is rotated counter-clockwise?

​​​​​​​

1. Right Postive, Left Negative

2. Right Negative, Left Positive
3. There is actually no current.
4. Can’t be determined

Q. Match the following devices to their corresponding energy conversions.

1. Mechanical to electrical
2. Electrical to mechanical
3. Electrical to light

Q. Live wire carries current at high voltage.

1. True
2. False

Q.

The middle finger in Fleming’s right-hand rule represents the direction of which quantity?

1. Motion of conductor

2. Flow of charges

3. Induced current

4. Magnetic field

Q. Inductors are not used in DC circuits. Find out the reason and write it down in the science diary.