When a proton is released from rest in a room, it starts with an initial acceleration ${\mathrm{a}}_0$ towards the east. When it is projected towards the north with a speed ${\mathrm{v}}_0$, it moves with initial acceleration $3{\mathrm{a}}_0$ towards east. The electric and magnetic fields in the room are -

1.  $\frac{{\mathrm{Ma}}_0}{\mathrm{e}}\mathrm{west},<mspace\; width="1em"></mspace>\frac{{\mathrm{Ma}}_0}{{\mathrm{ev}}_0}\mathrm{up}$

2.  $\frac{{\mathrm{Ma}}_0}{\mathrm{e}}\mathrm{west},<mspace\; width="1em"></mspace>\frac{2{\mathrm{Ma}}_0}{{\mathrm{ev}}_0}\mathrm{down}$

3.  $\frac{{\mathrm{Ma}}_0}{\mathrm{e}}\mathrm{east},<mspace\; width="1em"></mspace>\frac{2{\mathrm{Ma}}_0}{{\mathrm{ev}}_0}down$

4.  $\frac{{\mathrm{Ma}}_0}{\mathrm{e}}\mathrm{east},<mspace\; width="1em"></mspace>\frac{2{\mathrm{Ma}}_0}{{\mathrm{ev}}_0}up$

The unit of reduction factor of the tangent galvanometer is 

1. Ampere

2. Gauss

3. Radian

4. None of these

In order to pass 10% of the main current through a moving coil galvanometer of 99 ohms, the resistance of the required shunt is :

1. 9.9 Ω

2. 10 Ω

3. 11 Ω

4. 9 Ω

When a \(12~\Omega\) resistor is connected in parallel with a moving coil galvanometer, its deflection reduces from \(50\) divisions to \(10\) divisions. What will be the resistance of the galvanometer?
1. \(24~\Omega\)
2. \(36~\Omega\)
3. \(48~\Omega\)
4. \(60~\Omega\)

A voltmeter has a resistance of G ohms and range V volts. The value of resistance used in series to convert it into a voltmeter of range nV volts is :

1. nG

2. $(n-1)G$

3. $\frac{G}{n}$ 

4. $\frac{G}{(n-1)}$

A moving coil galvanometer has a resistance of 50 Ωand gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scale deflection for 1A :

1. 50/99 Ω in series

2. 50/99 Ω in parallel

3. 0.01 Ω in series

4. 0.01 Ω in parallel

The resistance of an ideal voltmeter is 

1. Zero

2. Very low

3. Very large

4. Infinite

The net resistance of a voltmeter should be large to ensure that :

A galvanometer having a resistance of \(8~\Omega\) is shunted by a wire of resistance \(2~\Omega\). If the total current is \(1~\text{A}\), the part of it passing through the shunt will be:
1. \(0.25~\text{A}\)
2. \(0.8~\text{A}\)
3. \(0.2~\text{A}\)
4. \(0.5~\text{A}\)

If an ammeter \(A\) reads \(2\) A and the voltmeter \(V\) reads \(20\) V, what is the value of resistance \(R\)? (Assuming finite resistances of ammeter and voltmeter)