A rectifier type AC voltmeter consists of a series resistance R, an ideal full-wave rectifier bridge and a PMMC instrument. The internal resistance of the instrument isΩ and a full- scale deflection is produced by a DC current of 1 mA. A voltage ofV (rms) is applied to the input terminals. The value of R required is?
a) 63.56 Ω
b) 89.83 Ω
c) 89.83 kΩ
d) 141.3 kΩ
Q.2.
A moving iron ammeter produces a full-scale torque ofμN-m with a deflection ofat a current ofA. the rate of change of self-inductance (μH/rad) of the instrument at full scale is?
a) 2.0 μH/rad
b) 4.8 μH/rad
c) 12.0 μH/rad
d) 114.6 μH/rad
Q.3.
A moving coil of a meter hasturns and a length and depth ofmm andmm respectively. It is positioned in a uniform radial flux density ofmT. The coil carries a current ofmA. The torque on the coil is?
a) 0.0216 N-m
b) 0.0456 N-m
c) 0.1448 N-m
d) 1 N-m
Q.4.
TwoμA full-scale PMMC meters are employed to construct aV and aV full-scale voltmeter. These meters will have figure of merit (sensitivities) as?
a) 10 kΩ/V and 10 kΩ/V
b) 100 kΩ/V and 10 kΩ/V
c) 10 kΩ/V and 100 kΩ/V
d) 10 kΩ/V and 1 kΩ/V
Q.5.
A PMMC rated asμA is used in a rectifier type of instrument which uses full wave rectification. What is the sensitivity on sinusoidal AC?
a) 4.5 kΩ/V
b) 18 kΩ/V
c) 10 kΩ/V
d) 9 kΩ/V
Q.6.
The discharge of a capacitor through a ballistic galvanometer produces a damped frequency of 0.Hz and successive swings ofand 76.8 mm. The damping ratio is?
a) 0.0568
b) 0.0887
c) 0.0357
d) 0.0441
Q.7.
The discharge of a capacitor through a ballistic galvanometer produces a damped frequency of 0.Hz and successive swings ofand 76.8 mm. The logarithmic decrement is?
a) 0.225
b) 0.565
c) 0.484
d) 0.7887
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.