The potential difference $\left({\mathrm{V}}_{\mathrm{B}}-{\mathrm{V}}_{\mathrm{A}}\right)$ between points A and B  in the figure is?  if $\mathrm{R}=0.7 \mathrm{\Omega }$ and i = 3 is

1.  3 V

2.  15 V

3.  5.1 V

4.  +5.1 V

A set of '\(n\)' equal resistors, of value '\(R\)' each, are connected in series to a battery of emf '\(E\)' and internal resistance '\(R\)'. The current drawn is \(I.\) Now, if '\(n\)' resistors are connected in parallel to the same battery, then the current drawn becomes \(10I.\) The value of '\(n\)' is:

A carbon resistor (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be:

1. Violet - Yellow - Orange - Silver

2. Yellow - Violet - Orange - Silver

3. Yellow - Green - Violet - Gold

4. Green - Orange - Violet - Gold

The figure shows a circuit that contains three identical resistors with resistance \(R = 9.0~\Omega\)$$ each, two identical inductors with inductance \(L = 2.0~\text{mH}\) each, and an ideal battery with emf \(\varepsilon = 18~\text{V}\). The current \('i'\) through the battery just after the switch is closed will be:
  
1. \(0.2~\text{A}\)
2. \(2~\text{A}\)
3. \(4~\text{A}\)
4. \(2~\text{mA}\)

The potential difference \(V_\mathrm{A}-V_\mathrm{B}\) between the points \(\mathrm{A}\) and \(\mathrm{B}\) in the given figure is:
    

A filament bulb (\(500\) W, \(100\) V) is to be used in a \(230\) V main supply. When a resistance\(R\) is connected in series, the bulb works perfectly and consumes \(500\) W. The value of \(R\) is:

Assertion : Electric conduction in gases is possible at normal pressure.
Reason : The electric conduction in gases depends only upon the potential difference between the electrodes.

Two metal wires of identical dimensions are connected in series. If \(\sigma_1~\text{and}~\sigma_2\) are the conductivities of the metal wires respectively, the effective conductivity of the combination is: