If the temperature of the cold junction of a thermocouple is lowered,then the neutral temperature

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:

$A$ cell of emf $E$ has an internal resistance $r$ and is connected to a rheostat. When the resistance $R$ of the rheostat is changed,which is the correct graph of the potential difference $V$ across it?

Two cables of copper are of equal lengths. One of them has a single wire of area of cross-section $A$, while the other has $10$ wires of cross-sectional area $A / 10$ each. Determine their suitability for transporting $A.C.$ and $D.C.$

The direction of current in an iron-copper thermocouple is

Assertion: In a simple battery circuit,the point of the lowest potential is the positive terminal of the battery.
Reason: The current flows towards the point of the higher potential,as it does in such a circuit from the negative to the positive terminal.