Question

A current-carrying straight conductor is placed in the east-west direction. What will be the direction of the force experienced by this conductor due to earth’s magnetic field? How will this force get affected on? (a) Reversing the direction of flow of current (b) Doubling the magnitude of current.

Answer 1

@Physics_Guru_Dev

Magnetic Effects of Electric Current

A current carrying straight conductor is placed in east-west direction. What will be the direction of the force experienced by this conductor due to earth's magnetic field? How will this force get affected on:
(i) reversing the direction of flow of current?
(ii)   doubling the magnitude of current?

The direction of earth’s magnetic field points from geographical south to geographical north. Given that, the current carrying straight conductor is placed in the east-west direction. Therefore, according to Fleming's left hand rule the current carrying conductor will deflect downwards.

(i) On reversing the direction of current, the conductor gets deflected in the upward direction. i.e., the direction of conductor reverses.

(ii) If the magnitude of current is doubled, it will result in doubling the magnitude of the force. 

Answer 2

Explanation:

The magnetic force acting on the wire is given by :

$F=I(L\times B)$

Where

I is the current flowing

L is the length of conductor

B is the magnetic field

Here, a current-carrying straight conductor is placed in the east-west direction. The direction of magnetic force can be found by using the Fleming's left hand rule. So, the direction of magnetic field is from south to the north.

(a) When the direction of flow of current is reversed, the direction of magnetic field gets reversed.

(b) When the magnitude of current is doubled, the magnitude of the force acting will be doubled.