Discussion Forum



1)

  In the circuit shown the cells A and B have negligible resistances. For VA 12V,R1 = 500 Ω and R = 100Ω the galvanometer  (G) shows no deflection. The value of VB is :

1142021960_download (1).png


A) 4 V

B) 2 V

C) 12 V

D) 6 V

Answer:

Option B

Explanation:

1142021478_download (2).png

Since deflection in galvanometer is zero so current will flow as shown in the above diagram.

Current I = $\frac{V_{A}}{R_{1}+R}$ = $\frac{12}{500+100}$ = $\frac{12}{600}$

So VB = IR = $\frac{12}{600}\times100$ = 2 V