Of the following graphs,the one that correctly represents the $I-V$ characteristics of an 'Ohmic device' is:

The $V-i$ graph for a conductor at temperatures $T_1$ and $T_2$ are as shown in the figure. $(T_2 - T_1)$ is proportional to

For a wire,$\frac{R}{l} = \frac{1}{2} \, \Omega/cm$ and the length of the wire is $l = 5 \, cm$. If a potential difference of $1 \, V$ is applied across it,the current through the wire will be: $(R = \text{Resistance})$ (in $A$)

The current flowing through a circuit is shown in the figure. What is the resistance of the circuit?

$A$ circuit to verify $Ohm's$ law uses an ammeter and a voltmeter. How should they be connected to the resistor?

The variation of current $(i)$ passing through a conductor as the voltage $(V)$ applied across its ends is varied is shown in the adjoining diagram. If the resistance $(R)$ is determined at the points $A, B, C$ and $D$,we will find that