The Peltier coefficient is $2 \times 10^{-9} \, V$. How much heat in $ergs$ is produced when a current of $2.5 \, A$ is passed for $2 \, minutes$?

In Circuit-$1$ and Circuit-$2$ shown in the figures,$R_1=1 \Omega, R_2=2 \Omega$ and $R_3=3 \Omega$. $P_1$ and $P_2$ are the power dissipations in Circuit-$1$ and Circuit-$2$ when the switches $S_1$ and $S_2$ are in open conditions,respectively. $Q_1$ and $Q_2$ are the power dissipations in Circuit-$1$ and Circuit-$2$ when the switches $S_1$ and $S_2$ are in closed conditions,respectively. Which of the following statement$(s)$ is(are) correct?
$(A)$ When a voltage source of $6 V$ is connected across $A$ and $B$ in both circuits,$P_2 > P_1$.
$(B)$ When a constant current source of $2 A$ is connected across $A$ and $B$ in both circuits,$P_1 > P_2$.
$(C)$ When a voltage source of $6 V$ is connected across $A$ and $B$ in Circuit-$1$,$Q_1 > P_1$.
$(D)$ When a constant current source of $2 A$ is connected across $A$ and $B$ in both circuits,$Q_1 > Q_2$.

If a battery of voltage $V$ is connected across terminals $I$ of the black box shown in the figure,an ideal voltmeter connected to terminals $II$ gives a reading of $V/2$. While if the battery is connected to terminals $II$,a voltmeter across terminals $I$ reads $V$. The black box may contain:

In the circuit shown in the figure,find the current through the $4\,\Omega$ resistor.

If in the circuit shown below,the internal resistance of the battery is $1.5 \, \Omega$ and $V_P$ and $V_Q$ are the potentials at $P$ and $Q$ respectively,what is the potential difference between the points $P$ and $Q$?

In the circuit of the adjoining figure,the current through the $12 \ \Omega$ resistor will be ................ $A$.