In the following circuit a 10 m long potentiometer wire with resistance 1.2 ohm/m, a resistance and an accumulator of emf 2V are connected in series. When the emf of thermocouple is 2.4 mV then the deflection in galvanometer is zero. The current supplied by the accumulator will be:

Options

A. `4 xx 10^(-4) A`
B. `8 xx 10^(-4)A`
C. `4 xx 10^(-3) A`
D. `8 xx 10^(-3) A`

Answer

A

Explanation

`E = xl = lrho l rArr I =E/(rho l) = (2.4 xx 10^(-3))/(1.2 xx 5) = 4 xx 10^(-4) A`