NCERT Class X Science Solutions: Chapter 13 – Magnetic Effects of Electric Current Part 1

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Question 1:

Which of the following correctly describes the magnetic field near a long straight wire?

  1. The field consists of straight lines perpendicular to the wire.

  2. The field consists of straight lines parallel to the wire.

  3. The field consists of radial lines originating from the wire.

  4. The field consists of concentric circles center on the wire.

Answer:

D. The field consists of concentric circles center on the wire.

On applying right-hand thumb rule, we find the direction of magnetic field. The field is in the form of concentric circles center on the wire carrying current.

Hence, the option (D) is correct.

Question 2:

The phenomenon of electromagnetic induction is

  1. The process of charging a body.

  2. The process of generating magnetic field due to a current passing through a coil.

  3. Producing induced current in a coil due to relative motion between a magnet and the coil.

  4. The process of rotating a coil of an electric motor.

Answer:

C. producing induced current in a coil due to relative motion between a magnet and the coil.

In electromagnetic induction phenomenon an induced current begins to flow in a coil whenever there is change in magnetic field in and around a coil.

Hence, the option (C) is correct.

Question 3:

The device used for producing electric current is called a

  1. Generator

  2. Galvanometer

  3. Ammeter

  4. Motor

Answer:

A. Generator.

An A.C. generator is the device used for producing an electric current.

Hence, the option (A) is correct.

Question 4:

The essential difference between an AC generator and a DC generator is that

  1. AC generator has an electromagnet while a DC generator has permanent magnet.

  2. DC generator will generate a higher voltage.

  3. AC generator will generate a higher voltage.

  4. AC generator has slip rings while the DC generator has a commentator

Answer:

D. AC generator has slip rings while the DC generator has a commentator

Image result for D. AC generator has slip rings while

Slip Rings While

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Question 5:

At the time of short circuit, the current in the circuit

  1. Reduces substantially.

  2. Does not change.

  3. Increases heavily.

  4. Vary continuously.

Answer:

C. increases heavily.

At the time of short circuiting the live wire and the neutral wire come into direct contact. As a result, the current in the circuit abruptly increases.

Hence, the option (C) is correct.