If R_{1} and R_{2} are the resistances of fil | vedclass

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

Question

(A) The power $P$ of an electrical appliance is given by the formula $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.Since both

Vedclass · Accepted Answer

$R_{2} = 2R_{1}$

Vedclass · Answer

(A) The power $P$ of an electrical appliance is given by the formula $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.Since both lamps are designed to operate on the same voltage $V$,we have $R = \frac{V^2}{P}$.For the first lamp,$P_{1} = 400 \ W$,so $R_{1} = \frac{V^2}{400}$.For the second lamp,$P_{2} = 200 \ W$,so $R_{2} = \frac{V^2}{200}$.Dividing $R_{2}$ by $R_{1}$,we get $\frac{R_{2}}{R_{1}} = \frac{V^2 / 200}{V^2 / 400} = \frac{400}{200} = 2$.Therefore,$R_{2} = 2R_{1}$.

If $R_{1}$ and $R_{2}$ are the resistances of filaments of a $400 \ W$ and a $200 \ W$ lamp,designed to operate on the same voltage,then

Similar Questions

Why is heat produced when a current is passed through a conductor?

The rating of an electric heater is $1100 \ W, 220 \ V$. Calculate its resistance when it operates at $220 \ V$. Also,calculate the energy consumed in $kWh$ in the month of November,if the heater is used daily for four hours at the rated voltage.

$(a)$ Name the effect of electric current which is utilised in the working of an electrical fuse.
$(b)$ How is a fuse connected in a domestic circuit?

An electric heater rated $600 \ W$ operates $6$ hours per day. Find the cost to operate it for $30$ days at ₹ $3.00$ per unit.

The unit $Joule/second$ $(J/s)$ is the unit of which of the following?

Vedclass Test Series

Exam Paper Generator

Online Exam Module