Current Given By A Cell - Practice Questions & MCQ

1.       Current supplied by the cell

• Cell supplies a constant current in the circuit.

$
i=\frac{E}{R+r}
$

$R$ - External resistance
$r$ - internal resistance
- Potential drop inside the cell=ir
- The internal resistance of the cell

$
r=\left(\frac{E}{V}-1\right) R
$

- Power dissipated in external resistance

$
P=\left(\frac{E}{R+r}\right)^2 R
$

- Maximum power is obtained when the resistance value of the load is equal in value to that of the voltage sources internal resistance.

Maximum power

$
P_{\max }=\frac{E^2}{4 r}
$