Practice Pakistan's most useful MCQs for competitive exams

At a certain frequency, the output voltage of a filter is 6 V and the input is 12 V. The voltage ratio in decibels is_____________?

• (A)  6.02 dB
• (B)  -6.02 dB
• (C)  12.04 dB
• (D)  -12.04 dB

Answer

Submitted By :Ali Uppal

A dynamo converts______________?

• (A)  mechanical energy into electrical energy
• (B)  electrical energy into mechanical energy
• (C)  magnetic energy into mechanical energy
• (D)  magnetic energy into electrical energy

Answer

Submitted By :Ali Uppal

cmf generated by A.C dynamo depends upon_____________?

• (A)  number of turns in the coil
• (B)  magnetic field strength
• (C)  frequency of rotation
• (D)  all of above

Answer

Submitted By :Ali Uppal

In a certain low-pass filter, fc = 3.5 kHz.if the input voltage is a 6 V sine wave with a dc level of 10 V, what is the output voltage magnitude?

• (A)  0 V
• (B)  5.97 V
• (C)  6 V
• (D)  597 mV

Answer

Submitted By :Ali Uppal

A parallel resonant band-pass filter consists of a 90 Ω resistor in series with a parallel network made up of a 60 mH coil and a 0.02 µF capacitor. The output is taken across the capacitor/coil. The coil winding has a resistance of 20 Ω. What is the center frequency of the filter?

• (A)  459 Hz
• (B)  4,591 Hz
• (C)  999 Hz
• (D)  2,176 Hz

Answer

Submitted By :Ali Uppal

An RL high-pass filter consists of a 470 Ω resistor and a 600 mH coil. The output is taken across the coil. The circuit’s critical frequency is___________?

• (A)  125 Hz
• (B)  1,250 Hz
• (C)  564 Hz
• (D)  5,644 Hz

Answer

Submitted By :Ali Uppal

An RC low-pass filter consists of a 120 Ω resistor and a 0.002 µF capacitor. The output is taken across the capacitor. The circuit’s critical frequency is___________?

• (A)  333 kHz
• (B)  633 kHz
• (C)  331 kHz
• (D)  60 kHz

Answer

Submitted By :Ali Uppal

In a certain low-pass filter, fc = 3.5 kHz. Its pass-band is_______________?

• (A)  0 Hz to 3.5 kHz
• (B)  0 Hz
• (C)  3.5 kHz
• (D)  7 kHz

Answer

Submitted By :Ali Uppal

An RC high-pass filter consists of an 820 Ω resistor. What is the value of C so that Xc is ten times less than Rat an input frequency of 12 kHz?

• (A)  81 µF
• (B)  161 µF
• (C)  0.161 µF
• (D)  220 µF

Answer

Submitted By :Ali Uppal

Inductors acts as a short circuit for_______________?

• (A)  AC
• (B)  DC
• (C)  Both A and B
• (D)  none of these

Answer

Submitted By :Ali Uppal