Resistors In Series And Parallel Combinations MCQ - Practice Questions with Answers

A, B and C are voltmeters of resistance R, 1.5R and 3R respectively as shown in the figure. When some potential difference is applied between X and Y, the voltmeter readings are V_A, V_B and V_C respectively. Then:

Two metal wires of identical dimensions are connected in series. If $\sigma_1$ and $\sigma_2$ are the conductivities of the metal wires respectively, the effective conductivity of the combination is:

A cell of e.m.f E volt with no internal resistance is connected to a wire whose cross-section changes. The wire has three sections of equal length. The middle section has a radius a, whereas the radius of the outer two sections is 2a. The ratio of the potential difference across section AB to the potential difference across section CA is

Two electric bulbs rated at $25 \mathrm{~W}, 200 \mathrm{~V}$ and $100 \mathrm{~W}, 200 \mathrm{~V}$ are connected in series across a 200 V source. The 25 W and 100 W bulb now draw $\mathrm{P}_1$ and $\mathrm{P}_2$ powers respectively, then -

Find the equivalent resistance of the network shown -

The resistance of the Series combination of two resistances is s. When they are joined in parables total resistance is P . If $s=n p$, then the minimum possible value of n is

In the two circuits as shown in the figure

A resistance of 2 is connected across one gap of a meter-bridge(the length of the wire is 100cm) and an unknown resistance, greater than 2  is connected across the other gap. When these resistances are interchanged, the unknown resistance is

The resistance of all the wires between any two adjacent dots is R. The equivalent resistance between A and B as shown in Fig. is