The current flowing through a copper voltameter is $1.5\ A$. If the surface area of the electrode plate is $50\ cm^2$,the thickness of the copper layer deposited on this surface in $20\ min$ will be: (Density of copper = $9000\ kg/m^3$ and Electrochemical equivalent of copper = $0.00033\ g/C$)

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,$Q_1 > Q_2$.

Two rods of copper $(Cu)$ and iron $(Fe)$ with the same cross-sectional area are joined at $S$ and a steady current $I$ flows through the rods as shown in the figure. Choose the most appropriate representation of charges accumulated near the junction $S$.

$A$ $3\,^oC$ rise in temperature is observed in a conductor by passing a certain current. When the current is doubled,the rise in temperature will be ............. $^oC$.

The heat evolved or absorbed at the junction when an electric current passes through the junction of two different metals is known as which effect?

The Peltier coefficient for the junction of a pair of metals is proportional to: