Question

Assertion: The voltage sensitivity may not necessarily increase on increasing the current sensitivity. Reason: Current sensitivity increases on increasing the number of turns of the coil. *​

Answer 1

Answer:

(D) Both assertion and reason are false.

Explanation:

Increasing the current sensitivity may not necessarily increase the voltage sensitivity.

Answer 2

Assertion: The voltage sensitivity may not necessarily increase by increasing the current sensitivity. Reason: Current sensitivity increases on increasing the number of turns of the coil.

In this both assertion and the Reason are True.

• The deflection induced in the galvanometer per unit flow of current is referred to as current sensitivity. It is provided by-

           $I_{s}$ = ∅ / I = nBA/C ----(1)

In this, (∅) shows the angle at which the galvanometer needle is diverted.

(I) shows the current processing through into the galvanometer.

(n) shows the number of revolves in the galvanometer's coil

(B) denotes the magnetic field around the coil.

(A) denotes the size of the coil's semicircle.

(C) denotes reimpose torque per unit twist

The deflection prompted inside the galvanometer whenever a constant potential difference is supplied across it is known as voltage sensitivity.

       It is provided by-   $V_{s}$ = ∅ / V = ∅/IR

        Here, V represents the possibility of a drop.

                  R stands for resistance.

• From eq (1) and eq (2), we get,

          $V_{s}$ = nBA/cR

• As an outcome, the current level of sensitivity is  

           $I_{s}$ = ∅ / I = nBA/c  and the sensitivity to voltage is  $V_{s}$ = nBA/cR

• As can be seen, voltage sensitivity is influenced by both current sensitivity and resistance. As a result, increasing current sensitivity may or may not change resistance. If we increase the number of revolves in the coil to enhance current sensitivity, the resistance will also rise.
• As a result, the voltage sensitivity in this circumstance may not be altered. There'll be no adjustment in the sensitivity of voltage if the sensitivity of current and resistivity grow or reduce in the same proportion. Therefore, a galvanometer's current responsiveness may not always enhance its voltage sensitivity.