The supply voltage to a room is $120\ V$. The resistance of the lead wires is $6\,\Omega$. $A$ $60\ W$ bulb is already switched on. What is the decrease in voltage across the bulb when a $240\ W$ heater is switched on in parallel to the bulb? ............. $V$

If $E$ denotes the electric field in a uniform conductor,$I$ the corresponding current through it,${v_d}$ the drift velocity of electrons,and $P$ the thermal power produced in the conductor,then which of the following graphs is incorrect?

Suppose switches $S_1, S_2$ and so on up to $S_6$ are closed one after another in order (first $S_1$,then $S_2$,etc.) at regular intervals of $1 \text{ minute}$ starting from $t = 0$. The graph of current versus time is best represented as:

Consider the following statements $A$ and $B$ and identify the correct answer given below.
$A$. Peltier coefficient is numerically equal to the potential difference across the junctions of the thermocouple through which current is flowing.
$B$. According to Thomson, energy is neither absorbed nor evolved at the junction of a thermocouple but is absorbed or evolved only along the lengths of both the conductors.

$A$ coil of wire of resistance $50\,\Omega$ is embedded in a block of ice. If a potential difference of $210\,V$ is applied across the coil,the amount of ice melted per second will be

$A$ cell having an emf $\varepsilon$ and internal resistance $r$ is connected across a variable external resistance $R$. As the resistance $R$ is increased,the plot of potential difference $V$ across $R$ is given by: