Chapter 13: Magnetic Effects of Electric Current- Exercise- 4

Science

(www.olympiadsuccess.com)

Chapter 13: Magnetic Effects of Electric Current

Class: X

Exercise 5

 

Question 1

State Fleming’s left-hand rule.

 

Answer 1

 

If we stretch the thumb, forefinger and middle finger of our left hand to make them mutually perpendicular. And then the first finger points in the direction of magnetic field and the second finger in the direction of current, the thumb will point in the direction of motion or the force which acts on the conductor. This is called Fleming’s left-hand rule.

 

 

 

Question 2

What is the principle of an electric motor?

Answer 2

Following is the principle on which an electric motor works. A current-carrying loop encounters a force and rotates when placed in a magnetic field. The direction of rotation of the loop is set by the Fleming’s left-hand rule.

Question 3

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is 1, towards south 2, towards east 3. downward 4. upward

Answer 3

4.upward. According to Fleming's left-hand rule, the direction of magnetic field is vertically upward,