Electrical Engineering Mcqs

An npn BJT has gm=38mA/v, cµ =10¯14 F, cπ =10¯13F and DC current gain β0=90.For this transistor fT & fβ are________?

• (A)  fT =1.64 x 108 Hz & fβ = 1.47 x 1010 Hz.
• (B)  fT =1.47 x 1010 Hz & fβ = 1.64 x 108 Hz
• (C)  fT =1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz
• (D)  fT =1.47 x 1010 Hz & fβ = 1.33 x 1012 Hz

Answer

Submitted By :Ali Uppal

The MOSFET switch in its on-state may be considered equivalent to_____________?

• (A)  resistor
• (B)  inductor
• (C)  capacitor
• (D)  battery

Answer

Submitted By :Ali Uppal

. If =0.98 ,Ico=6µA and Iβ=100µA for a transistor,then the value of Ic will be______?

• (A)  2.3mA
• (B)  3.2mA
• (C)  4.6 mA
• (D)  5.2mA

Answer

Submitted By :Ali Uppal

The signal voltage induced in the aerial of a radio receiver is of the order of_____________?

• (A)  mV
• (B)  µV
• (C)  V
• (D)  None of the above

Answer

Submitted By :Ali Uppal

In a transmitter ____________oscillator is used?

• (A)  Hartley
• (B)  RC phase-shift
• (C)  Wien-bridge
• (D)  Crystal

Answer

Submitted By :Ali Uppal

In an AM wave useful power is carrier by ______________?

• (A)  Carrier
• (B)  Sidebands
• (C)  Both sidebands and carrier
• (D)  None of the above

Answer

Submitted By :Ali Uppal

In an AM wave, the majority of the power is in _____________?

• (A)  Lower sideband
• (B)  Upper sideband
• (C)  Carrier
• (D)  None of the above

Answer

Submitted By :Ali Uppal

If modulation is 100% then signal amplitude is ____________arrier amplitude?

• (A)  Equal to
• (B)  Greater than
• (C)  Less than
• (D)  None of the above

Answer

Submitted By :Ali Uppal

In amplitude modulation, the _____________of carrier is varied according to the strength of the signal?

• (A)  Amplitude
• (B)  Frequency
• (C)  Phase
• (D)  None of the above

Answer

Submitted By :Ali Uppal

In pakistan, ______________ modulation is used for radio transmission?

• (A)  Frequency
• (B)  Amplitude
• (C)  Phase
• (D)  None of the above

Answer

Submitted By :Ali Uppal