EASY
Earn 100
Write the definition of figure of merit of Galvanometer.
Important Questions on Magnetic Effect of Current
EASY
Write the definition of figure of merit of Galvanometer.
MEDIUM
Distinguish between ammeter and voltmeter.
EASY
The number of turns in a coil of Galvanometer is tripled, then
HARD
Consider two identical galvanometers and two identical resistors with resistance . If the internal resistance of the galvanometers which of the following statement(s) about any one of the galvanometers is(are) true ?
MEDIUM
The range of an ammeter of resistance can be increased from to by connecting
MEDIUM
For full scale deflection of total divisions, voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity is will be:
EASY
Phosphor-bronze wire is used for suspension in a moving coil galvanometer, because it has:
EASY
A circuit contains an ammeter, a battery of 30 v and a resistance 40.8 ohm all connected in series. If the ammeter has coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be:
EASY
The deflection in galvanometer falls to $\left(\frac{1}{4}\right)^{\operatorname{th}}$ when it is shunted by . If additional shunt of is connected to earlier shunt, the deflection in galvanometer falls to
EASY
An ammeter of resistance can measure currents upto . The value of shunt resistance to measure current upto is
MEDIUM
The galvanometer deflection, when key is closed but is open, equals (see figure). On closing also and adjusting to the deflection in galvanometer becomes The resistance of the galvanometer is, then, given by [Neglect the internal resistance of battery]:
EASY
A galvanometer with its coil resistance requires a current of for its full deflection. In order to construct an ammeter to read up to a current of the approximate value of the shunt resistance should be:
MEDIUM
A galvanometer, whose resistance is , has divisions in it. When a current of A passes through it, its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range it should be connected to a resistance of:
EASY
The sensitivity of tangent galvanometer is increased, if
HARD
A moving coil galvanometer has 50 turns and each turn has an area . The magnetic field produced by the magnet inside the galvanometer is . The torsional constant of the suspension wire is . When a current flows through the galvanometer, a full scale deflection occurs if the coil rotates by . The resistance of the coil of the galvanometer is . This galvanometer is to be converted into an ammeter capable of measuring current in the range . For this purpose, a shunt resistance is to be added in parallel to the galvanometer. The value of this shunt resistance, in ohms, is . Write the value of , where is the greatest integer function.
EASY
Sensitivity of moving coil galvanometer is . If a shunt of of the resistance of galvanometer is connected to moving coil galvanometer, its sensitivity becomes
HARD
In a circuit for finding the resistance of a galvanometer by half deflection method, a battery and a high resistance of are used. The figure of merit of the galvanometer is . In the absence of shunt resistance, the galvanometer produces a deflection of divisions when current flows in the circuit. The value of the shunt resistance that can cause the deflection of , is closest to:
MEDIUM
The deflection in the galvanometer falls to when resistance is connected in parallel with it. What will be the deflection if an additional resistance of is connected in parallel with the above shunted galvanometer?
EASY
When a current of is passed through a galvanometer having a coil of resistance , it shows full-scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range is:
EASY
In a moving coil galvanometer, when the number of turns of the coil is doubled,
