$A$ silver voltmeter and a copper voltmeter are connected in parallel to a $12\ V$ battery. In $30\ minutes$,$1\ g$ of silver and $1.8\ g$ of copper are deposited. The power supplied by the battery is .... $(Z_{Cu} = 6.6 \times 10^{-4}\ g/C$ and $Z_{Ag} = 11.2 \times 10^{-4}\ g/C)$ (in $J/s$)

In the circuit shown,$E, F, G$,and $H$ are cells of e.m.f. $2\,V, 1\,V, 3\,V$,and $1\,V$ respectively,and their internal resistances are $2\,\Omega, 1\,\Omega, 3\,\Omega$,and $1\,\Omega$ respectively.

$A$ thermocouple is made from two metals,Antimony and Bismuth. If one junction of the couple is kept hot and the other is kept cold,then,an electric current will

The heater of an electric kettle is made of a wire of length $L$ and diameter $d$. It takes $4$ minutes to raise the temperature of $0.5 \ kg$ of water by $40 \ K$. This heater is replaced by a new heater having two wires of the same material,each of length $L$ and diameter $2d$. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by $40 \ K$?
$(A)$ $4$ if wires are in parallel
$(B)$ $2$ if wires are in series
$(C)$ $1$ if wires are in series
$(D)$ $0.5$ if wires are in parallel

Identify the correctness of the following statements:
$(1)$ The product of a volt and a coulomb is a joule.
$(2)$ The product of a volt and an ampere is a joule/second.
$(3)$ The product of a volt and a watt is a horsepower.
$(4)$ $A$ watt-hour can be measured in terms of an electron volt.

In an electrical cable,there is a single wire of copper with a radius of $9 \, mm$. Its resistance is $5 \, \Omega$. The cable is replaced by $6$ different insulated copper wires,each with a radius of $3 \, mm$. Now,the total resistance of the cable will be ............... $\Omega$.