A battery has e.m.f. 4V and internal resistance r. When this battery is connected to an external resistance of 2 Ω , a current of 1A flows in the circuit. How much current will flow if the terminals of the battery are connected directly

Question

A battery has e.m.f. 4V and internal resistance r. When this battery is connected to an external resistance of 2 Ω , a current of 1A flows in the circuit. How much current will flow if the terminals of the battery are connected directly (A) 1A (B) 2A (C) 4A (D) infinite

Tardigrade Admin · Accepted Answer

I = (E/R + r) or (R + r) = (E/I) = (4/I) = 4 ∴ r = 4 - R = 4 -2 = 2 Ω I = (E/r) = (4/2) = 2 A

Q. A battery has e.m.f. $4 V$ and internal resistance $r$ . When this battery is connected to an external resistance of $2 Ω$ , a current of $1 A$ flows in the circuit. How much current will flow if the terminals of the battery are connected directly

1A

2A

4A

infinite

I = $\frac{E}{R + r}$ or (R + r) = $\frac{E}{I} = \frac{4}{I}$ = 4
$∴$ r = 4 - R = 4 -2 = 2 $Ω$
I = $\frac{E}{r} = \frac{4}{2}$ = 2 A

Q. A battery has e.m.f. 4V and internal resistance r. When this battery is connected to an external resistance of 2Ω, a current of 1A flows in the circuit. How much current will flow if the terminals of the battery are connected directly

1A

2A

4A

infinite

I = R+rE​ or (R + r) = IE​=I4​ = 4 ∴ r = 4 - R = 4 -2 = 2 Ω I = rE​=24​ = 2 A

Q. A battery has e.m.f. $4 V$ and internal resistance $r$ . When this battery is connected to an external resistance of $2 Ω$ , a current of $1 A$ flows in the circuit. How much current will flow if the terminals of the battery are connected directly

I = $\frac{E}{R + r}$ or (R + r) = $\frac{E}{I} = \frac{4}{I}$ = 4
$∴$ r = 4 - R = 4 -2 = 2 $Ω$
I = $\frac{E}{r} = \frac{4}{2}$ = 2 A