he power dissipated in the circuit shown in the figure is $30\,W$. The value of $R$ is ............. $\Omega$
$10$
$15$
$20$
$25$
An electric bulb of $500 \,watt$ at $100\, volt$ is used in a circuit having a $200\, {V}$ supply. Calculate the resistance ${R}$ to be connected in series with the bulb so that the power delivered by the bulb is $500\, {W}$. (in $\Omega$)
How many calories of heat will be produced approximately in a $210\, watt$ electric bulb in $5$ minutes .............. $cal $
The resistance of hot tungsten filament is about $10$ times the cold resistance. What will be the resistance of $100\, W$ and $200\, V$ lamp when not in use ............. $\Omega $
Two bulbs $X$ and $Y$ having same voltage rating and of power $40\, watt$ and $60\, watt$ respectively are connected in series across a potential difference of $300\, volt$, then
Resistances are arranged in a cyclic order to form a balanced wheatstone bridge as shown in figure. Ratio of power consumed in the branches $P + Q$ and $R + S$ is