When a proton is released from rest in a room, it starts with an initial acceleration towards the east. When it is projected towards the north with a speed , it moves with initial acceleration towards east. The electric and magnetic fields in the room are -
1.
2.
3.
4.
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 Ω 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 Ω
2. 36 Ω
3. 48 Ω
4. 60 Ω
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)
(3)
(4)
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 :
1. | It does not get overheated |
2. | It draws excessive current |
3. | It can measure large potential difference |
4. | It does not appreciably change the potential difference to be measured |
A galvanometer having a resistance of 8 ohms is shunted by a wire of resistance 2 ohms. If the total current is 1 amp, the part of it passing through the shunt will be :
(1) 0.25 amp
(2) 0.8 amp
(3) 0.2 amp
(4) 0.5 amp
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)
1. | Exactly 10 ohm |
2. | Less than 10 ohm |
3. | More than 10 ohm |
4. | We cannot definitely say |