Practice Pakistan's most useful MCQs for competitive exams

In a series–parallel circuit consisting of R1 and R2 in series and connected in parallel with R3, if R1 opens, then R2‘s voltage will:___________?

• (A)  increase
• (B)  remain the same
• (C)  decrease
• (D)  cannot tell

Answer

Submitted By :Ali Uppal

In a series resonant band-pass filter, a lower value of Q results in______________?

• (A)  a higher impedance
• (B)  a smaller bandwidth
• (C)  a higher resonant frequency
• (D)  a larger bandwidth

Answer

Submitted By :Ali Uppal

The maximum output voltage of a certain low-pass filter is 15 V. The output voltage at the critical frequency is_____________?

• (A)  10.60 V
• (B)  0 V
• (C)  21.21 V
• (D)  15 V

Answer

Submitted By :Ali Uppal

The same signal in Problem 2 is applied to an RC high-pass filter. If the reactance is zero at the input frequency, the output voltage is____________?

• (A)  12.73 V peak-to-peak
• (B)  18 V peak-to-peak
• (C)  9 V peak-to-peak
• (D)  zero

Answer

Submitted By :Ali Uppal

A sinusoidal voltage with a peak-to-peak value of 18 V is applied to an RC low-pass filter. If the reactance at the input frequency is zero, the output voltage is____________?

• (A)  18 V peak-to-peak
• (B)  zero
• (C)  9 V peak-to-peak
• (D)  12.74 V peak-to-peak

Answer

Submitted By :Ali Uppal

Vout = 500 mV, and Vin = 1.3 V. The ratio Vout/ Vin expressed in dB is__________?

• (A)  0 dB
• (B)  8.30 dB
• (C)  -8.30 dB
• (D)  0.8 dB

Answer

Submitted By :Ali Uppal

A parallel resonant band-pass filter consists of a 6.8 Ω resistor in series with a parallel network made up of an 8 µH coil and a 120 pF capacitor. The output is taken across the capacitor/coil. Assume RW = 0 Ω. What is the center frequency of the filter?

• (A)  5.14 MHz
• (B)  514 kHz
• (C)  5.03 MHz
• (D)  503 kHz

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

An RL low-pass filter consists of a 5.6 mH coil and a 3.3 kΩ resistor. The output voltage is taken across the resistor. The circuit’s critical frequency is______________?

• (A)  93.8 kHz
• (B)  93.8 Hz
• (C)  861 Hz
• (D)  86.12 kHz

Answer

Submitted By :Ali Uppal

An RC high-pass filter consists of a 0.2 µF capacitor and a 220 Ω resistor. The output is taken across the resistor. The circuit’s critical frequency is_____________?

• (A)  723 Hz
• (B)  7,234 Hz
• (C)  362 Hz
• (D)  3,617 Hz

Answer

Submitted By :Ali Uppal