A cell of emf 10 V and the internal resistance 1 Ω is being charged by an external supply of 100 V. An external resistance of 8 Ω is connected to the charging circuit. The current in the circuit is

10 A

The correct answer is Option (4) → 10 A

Given:

Emf of cell, $E = 10\ V$

Internal resistance, $r = 1\ \Omega$

External voltage, $V = 100\ V$

External resistance, $R = 8\ \Omega$

During charging:

The effective emf in the circuit = $(V - E)$

Total resistance = $(R + r)$

Hence, current

$I = \frac{V - E}{R + r}$

$I = \frac{100 - 10}{8 + 1} = \frac{90}{9} = 10\ A$

Therefore, the current in the circuit is 10 A.