92. In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of

A. R only

B. L only

C. C only

D. L or C

93. In a series L-C circuit at the resonant frequency the

A. current is maximum

B. current is minimum

C. impedance is maximum

D. voltage across C is minimum

94. In a R-L-C series circuit if voltage V across the cirucit is reduced to half the current I will change to

A.21

B. ?

C. 3/4 I

D. 5/8 I

95. The time constant of a series R-C circuit is given by

A. R/C

B. RC2

C. RC

D. R2C

96. If resistance is 20f-a and inductance is 2H in a R-L series circuit, then time constant of this circuit will be

A. 0.001 s

B. 0.1 s

C. 10 s

D. 100 s

97. Which of the following coil will have large resonant frequency?

A. A coil with large resistance

B. A coil with low resistance

C. A coil with large distributed capacitance

D. A coil with low distributed capacitance

98. If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equationrepresents this wave?

A. 42.42 win 314 t

B. 60 sin 25 t

C. 30 sin 50 t

D. 84.84 sin 25 t

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