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

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.

In the circuit diagram shown,the two resistance wires $A$ and $B$ are of the same length and same material,but $A$ is thicker than $B$. Which ammeter,$A_{1}$ or $A_{2}$,will indicate a higher reading for current? Give a reason.

Mention one reason why tungsten is used for making the filament of an electric lamp.

Calculate the resistance of an electric bulb which allows a $10 \ A$ current when connected to a $220 \ V$ power source. (in $Omega$)

$A$ child has drawn the electric circuit to study Ohm's law as shown in the figure. His teacher told him that the circuit diagram needs correction. Study the circuit diagram and identify the errors,then describe the correct circuit configuration.

Vedclass Test Series

Exam Paper Generator

Online Exam Module