Two equal resistances when connected in serie | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let the value of each resistance be $R$ and the voltage of the battery be $V$.In series combination,the equivalent resistance is $R_s = R + R = 2R

Vedclass · Accepted Answer

$240$

Vedclass · Answer

(B) Let the value of each resistance be $R$ and the voltage of the battery be $V$.In series combination,the equivalent resistance is $R_s = R + R = 2R$.The power consumed in series is $P_s = \frac{V^2}{R_s} = \frac{V^2}{2R} = 60 \ W$.From this,we get $\frac{V^2}{R} = 120 \ W$.In parallel combination,the equivalent resistance is $R_p = \frac{R 	imes R}{R + R} = \frac{R}{2}$.The power consumed in parallel is $P_p = \frac{V^2}{R_p} = \frac{V^2}{R/2} = 2 	imes \frac{V^2}{R}$.Substituting the value of $\frac{V^2}{R} = 120 \ W$,we get $P_p = 2 	imes 120 = 240 \ W$.

Two equal resistances when connected in series to a battery,consume electric power of $60 \ W$. If these resistances are now connected in parallel combination to the same battery,the electric power consumed will be...........$W$

Similar Questions

The velocities of three particles of masses $20 \ g$,$30 \ g$ and $50 \ g$ are $10 \hat{i}$,$10 \hat{j}$ and $10 \hat{k}$,respectively. The velocity of the centre of mass of the three particles is

The equation of the circle which passes through the origin and cuts orthogonally each of the circles $x^2+y^2-6x+8=0$ and $x^2+y^2-2x-2y-7=0$ is

In a potentiometer, a wire of length $10 \, m$ having resistance $50 \, \Omega$ is used. $A$ battery of $5 \, V$ and a resistor of $450 \, \Omega$ are connected in series to the wire. If an unknown battery of emf $E$ balances the potentiometer at $450 \, cm$, then the value of $E$ is (in $V$)

The acute angle between the line $\vec{r}=(\hat{i}+2\hat{j}+\hat{k})+\lambda(\hat{i}+\hat{j}+\hat{k})$ and the plane $\vec{r} \cdot(2\hat{i}+\hat{j}+\hat{k})=5$ is

In the circuit shown in the figure, what is the value of $I_1$ just after pressing the key $K$?

Vedclass Test Series

Exam Paper Generator

Online Exam Module