Together With Science

Book: Together With Science

Chapter: 13. Magnetic Effects of Electric Current

Subject: Physics - Class 10th

Q. No. 9 of Assess Yourself

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9

How many times, the current produced by AC Generator reverses its direction in one complete revolution of its coil?

AC generator supplies AC current. To determine how many times the direction of an Alternating Current changes we have to find out about its frequency. Frequency of an AC current implies number of complete waves present in a second. If the coil completes one revolution in one second then the frequency of the AC generator is said to be 1 hertz. The given picture will clear the concept,


hertz.pngIn the picture there is only one complete wave in a second, hence its frequency is 1 hertz. Which means that the coil has completed one revolution. Hence we can that in one revolution the current change its direction twice first positive than negative.


More Exercise Questions

1

The magnetic force on a moving proton acts towards north in a horizontal plane. If the proton is moving vertically upward then what will be the direction of magnetic field?
2

A charged particle moves in a clockwise direction in a magnetic field which is perpendicular to plane of paper directed downwards. What is the nature of charged particle?
3

Give one application of electromagnetic induction.
4

Suppose a coil is place in a changing magnetic field and the circuit is not closed will the current induce in the coil?
5

In domestic electric circuit, with which wire we connect a fuse?
6

Core of an electromagnet must be of soft iron but not steel. Justify it.
7

What happens to the force experienced by a current carrying conductor placed in a uniform magnetic field, when placed

(a) parallel to magnetic field?


(b) perpendicular to magnetic field?
8

With the help of neat diagram describe how you can generate induced current in the circuit.
9

How many times, the current produced by AC Generator reverses its direction in one complete revolution of its coil?
9

How many times AC supply in India reversed its direction in one second.
10

State the disadvantage of direct current.
11

List four characteristic features of circuits used in the residential buildings.
12

State the three factors on which the magnitude of magnetic field due to current carrying solenoid depends?
13

Write one application of each of the following:

(a) Right-Hand Thumb Rule


(b) Fleming’s Left-Hand Rule


(c) Fleming’s Right-Hand Rule
14

State the difference between Fleming’s Left-Hand Rule and Fleming’s Right-Hand Rule. Name the electrical devices where these rules find an important application.
15

State the rule to determine the direction of a

magnetic field produced around a straight conductor carrying current.
15

State the rule to determine the direction of a

force experienced by a current carrying straight conductor placed in a magnetic field which is perpendicular to it.
15

State the rule to determine the direction of a

current induced in coil due to its rotation in a magnetic field.
16

What is short circuiting? State one factor/condition that can lead to it. Name a device in the household that acts as a safety measure for it. State the principle of its working.
17

State the safety measures in using electricity.
18

Distinguish between a bar magnet and a solenoid.
19

How can a magnetic field be produced without using a magnet?
19

Describe an activity with labelled diagram to show that a current carrying conductor experiences a force in a magnetic field.
19

State the rule to determine the direction of force.
20

Explain the various part of AC generator.
20

What is the difference between direct current generator and alternating current generator?
21

Mr. Sharma used to park his car in the basement of his house. One day in the morning he noticed that his basement is full of knee-deep water and its walls were wet because of the hours-long rain at night. When he entered the basement, he experienced a major shock. His father seeing him from outside, rushed to the main switch and switched it off and thus saved his life.

(a) Why Mr. Sharma experienced the shock?


(b) What precautions should Mr. Sharma take to avoid such incidences in future?


(c) Which qualities were shown by Mr. Sharma’s father?

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