To increase the current sensitivity of a moving coil galvanometer by 50% its resistance is increased so that, The new resistance becomes twice its initial resistance . By what factor does it voltage sensitivity change

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

decreases by 20%

Increases by 15%

decreases by 25%

Increases by 25%

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Current sensitivity $S_{i} = \frac{nBA}{e}$

$∴ \frac{n_{1} {BA}_{1}}{e} = 1 .5 \times \frac{nBA}{e} \Rightarrow n_{1} A_{1} = \frac{3}{2} nA . ......... (1)$

$Now R_{1} = 2 R$

New voltage sensitivity, $\begin{array}{l} S_{v}' = \frac{θ}{v'} = \frac{θ}{{iR}_{1}} = \frac{n_{1} {BA}_{1}}{{eR}_{1}} = \frac{\frac{3}{2} nBA}{c \times 2 R} \\ \Rightarrow S_{v}' = \frac{3}{4} . S_{v} \end{array}$

Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

🔥 Start Your JEE/NEET Prep at Just ₹1999 / month - Limited Offer! Check Now!

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET