Question

In the circuit , the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, the value of the resistor R will be(a) 100 Ω(b) 200 Ω(c) 1000 Ω(d) 500 Ω

Answer 1

Answer:

100 Ω

Explanation:

In the circuit , the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, the value of the resistor R will be(a) 100 Ω(b) 200 Ω(c) 1000 Ω(d) 500 Ω

the galvanometer G shows zero deflection , if no current flows through it

so no potential difference across it.

=> Potential difference across R should be 2V

Potential Difference across R =   (R)/(R + 500)  * 12

=> (R)/(R + 500)  * 12 = 2

=> 6R = R + 500

=> 5R = 500

=> R = 100

the value of the resistor R will be(a) 100 Ω