Question

Three equal resistances each of $R$ ohm are connected as shown in figure. A battery of $2$ volts of internal resistance $0.1$ ohm is connected across the circuit. Calculate the value of $R$ for which the heat generated in the external circuit is maximu.

• A. $0.1\Omega$
• B. $0.2\Omega$
• C. $0.3\Omega$
• D. $0.4\Omega$

Answer 1

The correct option is C $0.3\Omega$

The equivalent circuit will be:

Equivalent resistance=$R\parallel R\parallel R$

$=\frac{R}{3}$

For heat generated to be maximum,

$\frac{R}{3}=\mathrm{0..1}\Omega$

$R=0.3\Omega$