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.
Draw a schematic diagram of an electric circuit consisting of a battery of two cells each of $1.5\, V$, $5\, \Omega, 10\, \Omega$ and $15\, \Omega$ resistors and a plug key, all connected in series.
A large number of free electrons are present in metals yet no current flows in the absence of electric potential across it. Explain the statement with reason.
Two conductors, one having resistance $R$ and another $2 R$ are connected in turn across a $dc$ source. If the rate of heat produced in the two conductors is $Q_{1}$ and $Q_{2}$ respectively, what is the value of $Q_{1} / Q_{2}$ ?
$100 \,J$ of heat is produced each second in a $4\, \Omega$ resistance. Find the potential difference across the resistor.