In the following star circuit diagram (figure), the equivalent resistance between the points A and H will be

(1) 1.944 r

(2) 0.973 r

(3) 0.486 r

(4) 0.243 r

In the circuit of adjoining figure the current through 12 Ω resister will be

(1) 1 A

(2) $\frac{1}{5}A$

(3) $\frac{2}{5}A$

(4) 0 A

The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is :

(1) 4

(2) 3

(3) 2

(4) 1

Which of the adjoining graphs represents ohmic resistance ?

(1)

(2)

(3)

(4)

Variation of current passing through a conductor with the voltage applied across its ends varies is shown in the diagram below. If the resistance (R) is determined at points A, B, C and D, we will find that:

The voltage V and current I graph for a conductor at two different temperatures T₁ and T₂ are shown in the figure. The relation between T₁ and T₂ is :

(1) T₁ > T₂

(2) $T_1\approx T_2$

(3) T₁ = T₂

(4) T₁ < T₂

From the graph between current \(I\) and voltage \(V\) shown below, identify the portion corresponding to negative resistance 

1. \(AB\)
2. \(BC\)
3. \(CD\)
4. \(DE\)

I-V characteristic of a copper wire of length L and area of cross-section A is shown in figure. The slope of the curve becomes :

(1) More if the experiment is performed at higher temperature

(2) More if a wire of steel of same dimension is used

(3) More if the length of the wire is increased

(4) Less if the length of the wire is increased

E denotes electric field in a uniform conductor, I corresponding current through it, V_d drifts velocity of electrons and P denotes thermal power produced in the conductor, then which of the following graph is incorrect :

(1)

(2)

(3)

(4)

The two ends of a uniform conductor are joined to a cell of e.m.f. E and some internal resistance. Starting from the midpoint P of the conductor, we move in the direction of current and return to P. The potential V at every point on the path is plotted against the distance covered (x). Which of the following graphs best represents the resulting curve

(1)

(2)

(3)

(4)