In the figure given, the electric current flowing through the 5 $\mathrm{k} \Omega$ resistor is ' x ' mA . The value of x to the nearest integer is ____

JEE Main · 2021 · 16 Mar 2021 · Shift 1 · Current Electricity

In the figure given, the electric current flowing through the 5

k Ω

resistor is ' x ' mA . The value of x to the nearest integer is ____

Answer: 3

The three

3 k Ω

resistors are joined across the same pair of points, so together they amount to

\frac{3}{3} = 1 k Ω

. That combination sits in series with the

5 k Ω

resistor and with the

1 k Ω

internal resistance of the cell, giving

R = 5 + 1 + 1 = 7 k Ω

The

5 k Ω

resistor lies in the single branch that carries the whole current, so

I = \frac{21}{7 \times 1 0 ^{3}} = 3 \times 1 0^{- 3} A

The current through it is 3 mA, so

x = 3

JEE Main · 2021 · 16 Mar 2021 · Shift 1 · Integer answer