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

**Answer:-**

(i) Potential difference (

*V)*= 6 V Here 1 Ω and 2 Ω resistors are connected in series.

∴ equivalent resistance of the circuit (

*R)*= 1 + 2 = 3 ΩAccording to Ohm’s law

*V*=

*IR*

Or I=V/R=6/3=2A

the current through the circuit (I)=2A

Now the power used in the 2 Ω resistor

we know that Power = I

^{2}R = 2×2×2=8W

(ii) Potential difference,

*V*= 4 V12 Ω and 2 Ω resistors are connected in parallel. The voltage across each component of a parallel circuit remains the same. Hence, the voltage across 2 Ω resistor will be 4 V. Power consumed by 2 Ω resistor is given by

∴ the power used by 2 Ω resistor is 8 W.