The ratio of powers dissipatted respectively in $R$ and $3R$, as shown is:
$9$
$27/4$
$4/9$
$4/27$
$4$ bulbs marked $40\, W$, $250\, V$ are connected in series with $250\, V$ mains. The total power is ............. $W$
The power rating of an electric motor which draws a current of $3.75\, amperes$ when operated at $200\, V$ is about
In the circuit shown in figure, the power which is dissipated as heat in the $6\,\Omega$ resistor is $6\,W$. What is the value of resistance $R$ in the circuit?................... $\Omega$
The resistive network shown below is connected to a $D.C.$ source of $16\, V$. The power consumed by the network is $4\, Watt$. The value of $R$ is ............. $\Omega$
An electric bulb rated as $200\, {W}$ at $100 \,{V}$ is used in a circuit having $200\, {V}$ supply. The resistance $'R'$ that must be put in series with the bulb so that the bulb delivers the same power is $.....\,\Omega$