Electrical and ...

A 2 A full scale PMMC type dc ammeter has a voltage drop of 100 mV at 2 A. The meter can be converted into a 10 A full scale dc ammeter by connecting a

Assume that for a moving iron instrument, the self-inductance of the coil increases uniformly by an amount of 2.51 mH within 0° to 90°. The controlling spring constant is 10 μNm/degree. If 1 A current flows through the coil, the deflection (in degrees) is _______ 

If current in the fixed coil and the moving coil of an electrodynamic instrument are 5 mA and 4 mA, then 60° deflection is produced. If we connect the fixed and moving coil in series and pass 3 mA current through them, the deflection (in degree) will be _______

A voltmeter having a sensitivity of 500 Ω/V reads 75 V on its 100 V scale when connected across an unknown resistor in series with a multi-ammeter. When the ammeter reads 2.5 mA, the error (in %) due to the loading effect of the voltmeter is

A PMMC instrument has 100 turns in its moving coil. The length of the coil is 1.25 cm and the width of the coil is 1 cm. The airgap flux density is 0.8 wb/m². If the coil carries 2 mA current, the sensitivity of the instrument in degree/mA is _______

The capacitance of a simple electrostatic instrument increases from 80 pF to 95.7 pF, when the coil moves from 95° to 104°. The spring constant is 2 μNm/degree. When the instrument is used to measure unknown voltage, the pointer moves to 100°. The value of unknown voltage (in V) _______

In an electrodynamic ammeter, the mutual inductance between the fixed and moving coil is found to vary as \(500\sin \left( {\theta - \frac{{2\pi }}{9}} \right)\mu H\), where θ denotes the deflection of the moving coil in radian. When a current of 200 mA is flowing through the meter, the deflection is found to be θ = 100°. The spring constant of the meter in μNm/degree is ______ (up to two decimal places)