The production of $e.m.f.$ by maintaining a difference of temperature between the two junctions of two different metals is known as

The two ends of a conductor are connected to a cell having an $e.m.f. \ E$ and some internal resistance. Starting from the midpoint $P$ of the conductor,moving in the direction of the current,and returning to point $P$,which of the following graphs best represents the potential $V$ versus the distance $x$ covered along the path?

$A$ 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:

$A$ conductor is made of an isotropic material and has the shape of a truncated cone. $A$ battery of constant emf is connected across it and its left end is earthed as shown in the figure. If at a section distant $x$ from the left end, electric field intensity, potential, and the rate of generation of heat per unit length are $E, V$, and $H$ respectively, which of the following graphs is/are correct?

In an electroplating experiment,a current of $4 \ A$ is passed for $2 \ min$ to deposit a mass $m$ of silver. If a current of $6 \ A$ is passed for $40 \ s$,the mass of silver deposited is:

$A$ steel wire has a resistance twice that of an aluminium wire. Both of them are connected to a constant voltage supply. More heat will be dissipated in: