Question

The amount of deflection of the magnetic needle in a galvanoscope depends on
(A) The amount of current passing through the insulated copper wire that is wound over it
(B) Magnetic strength of the magnetic needle
(C) Number of turns of the coil
(D) All the above

Answer 1

Hint The answer to this question should be made with the help of the knowledge about galvanoscope. The galvanoscope is defined as an instrument which is used to detect the existence of an electric current and to determine the direction of the electric current as well.

Complete step by step answer:
We know that,
The deflection in galvanometer is defined by: $\tau = NBIA$
The ‘N’ is noted as the number of turns of coils.
‘B’ is noted as the magnetic strength of magnetic needles.
‘I’ is noted as the amount of current passing through the insulated copper wire that is wound over it.
‘A’ is noted as an area of coil contact with a magnetic field.
So, the amount of deflection of the magnetic needle in a galvanoscope depends on: the amount of current passing through the insulated copper wire that is wound over it, magnetic strength of the magnetic needle and the number of turns of the coil.

Hence, the correct answer is Option D.

Note The basic galvanoscope has only one single turn which is made up with the wire, in order to set up the magnetic field which then turns the magnetic needle. The galvanoscope is very sensitive and if we increase the number of turns of the wire in the loop surrounding the needle, then the galvanoscope becomes more sensitive.