A heater $A$ gives out $300\, W$ of heat when connected to a $200\, V$ $d.c.$ supply. Asecond heater $B$ gives out $600\, W$ when connected to a $200\,v$ $d.c$. supply. If a series combination of the two heaters is connected to a $200\, V$ $d.c$. supply the heat output will be ................. $W$
$100$
$450$
$300$
$200$
The energy consumed in $1\, Kwatt$ electric heater in $30$ seconds will be
According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to
Three resistors of $4\,\Omega ,6\,\Omega $ and $12\,\Omega $ are connected in parallel and the combination is connected in series with a $1.5\, V$ battery of $1\,\Omega $ internal resistance. The rate of Joule heating in the $4\,\Omega $ resistor is ................ $W$
A bulb has specification of one kilowatt and $250\, volts$, the resistance of bulb is .................. $\Omega$
In the circuit shown, the resistance $r$ is a variable resistance. If for $r = fR,$ the heat generation in $r$ is maximum then the value of $f$ is