A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is…

A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is deflection of 40 divisions when R.B.=2400 Ω. Deflection becomes 20 divisions when resistance taken from resistance box is 4900 Ω. Then we can conclude :



Note: This question is awarded as the bonus. Now the question is corrected.

  1. Current sensitivity of galvanometer is 20 μA/division
  2. Resistance of galvanometer is 200 Ω.
  3. Resistance required on R.B. for a deflection of 10 divisions is 9800 Ω.
  4. Full scale deflection current is 2 mA.

Solution

Current in the circuit,

I=V2400+RG and I2=V4900+RG

⇒RG=100Ω

I=22500=8×10-4A

Current Sensitivity =8×10-440

20μA per division

Asked in: JEE Main 2016 (10 Apr Online)

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