Question

14. Compare the power used in the 20 resistor in each of the following circuits:
(i) a 6 V battery in series with 1 and 2 resistors, and (ii) a 4 V battery in parallel
with 12 1 and 2 Q resistors.​

Answer 1

$\bf\huge{Answer}$

Potential difference, V = 6 V

20 Ohm resistors are connected in series.

Therefore, equivalent resistance of the circuit, R = 1 + 2 = 3 Ohm

According to Ohm’s law,

V = IR

Where,

I is the current through the circuit

I= 6/3 = 2 A

This current will flow through each component of the circuit because there is no division of current in series circuits. Hence, current flowing through the 2Ohm resistor is 2 A. Power is given by the expression,

$P= (I)^2R = (2)2 x 2 = 8 W$

(ii) Potential difference, V = 4 V

12 Ohm and 2 Ohm resistors are connected in parallel. The voltage across each component of a parallel circuit remains the same.

Hence, the voltage across 2 Ohm resistor will be 4 V.

Power consumed by 2 Ohm resistor is given by

[tex]P= V2/R= 42/2 = 8 W

Therefore, the power used by 2 Ohm resistor is 8 W.