Question

If the current sensitivity of a moving coil galvanometer is increased by 20% , its resistance also increases by 1.5 times .How will the voltage sensitivity of galvamometer be affected?

Answer 1

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Answer 2

Answer:

20% will the voltage sensitivity of galvanometer be affected.

Step-by-step explanation:

Given : If the current sensitivity of a moving coil galvanometer is increased by 20% , its resistance also increases by 1.5 times.

To find : How will the voltage sensitivity of galvanometer be affected?  

Solution :

Let r be the resistance.

Its resistance also increases by 1.5 times.

i.e. $r'=1.5r$

Let I be the current.

If the current sensitivity of a moving coil galvanometer is increased by 20%.

$I'=I+20\%I\\I'=I+0.2I\\I'=1.2I$

Initial voltage intensity is given by,

$V'=\frac{I'}{r'}$

Substitute the value,

$V'=\frac{1.2I}{1.5r}$

$V'=0.8V$

$\frac{V'}{V}=0.8$

Percentage increase in voltage sensitivity is given by,

$=(1-\frac{V'}{V})\times 100$

$=(1-0.8)\times 100$

$=0.2\times 100$

$=20\%$

Therefore, 20% will the voltage sensitivity of galvanometer be affected.