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Electronic Devices & Circuits Mcqs

Q:

Consider a peak rectifier fed by a 60-Hz sinusoid having a peak value Vp = 100 V. Let the load resistance R = 10 k?. Calculate the fraction of the cycle during which the diode is conducting

A) 1.06 % B) 2.12 %
C) 3.18% D) 4.24%
 
Answer & Explanation Answer: C) 3.18%

Explanation: w ?t ~ ?(2Vr/Vp)
? = ?(2 X 2/100)
? = 0.2 rad or 3.18% of the cycle

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2739
Q:

For a half wave or full wave rectifier the Peak Inverse Voltage of the rectifier is always

A) Greater than the input voltage B) Smaller than the input voltage
C) Equal to the input voltage D) Greater than the input voltage for full wave rectifier and smaller for the half wave rectifier
 
Answer & Explanation Answer: B) Smaller than the input voltage

Explanation: The peak input voltage is smaller than the input voltage due to the presence of diode(s). A single diode reduces the output voltage by approximately 0.7V.

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849
Q:

A simple diode rectifier has ‘ripples’ in the output wave which makes it unsuitable as a DC source. To overcome this one can use

A) A capacitor in series with a the load resistance B) A capacitor in parallel to the load resistance
C) Both of the mentioned situations will work D) None of the mentioned situations will work
 
Answer & Explanation Answer: B) A capacitor in parallel to the load resistance

Explanation: A capacitor is parallel with a resistor can only makes ripples go away. Series connection will become equal to an open circuit once the capacitor is fully charged.

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445
Q:

If peak voltage for a half wave rectifier circuit is 5V and diode cut in voltage is 0.7, then peak inverse voltage on diode will be?

A) 5V B) 4.9V
C) 4.3V D) 6.7V
 
Answer & Explanation Answer: C) 4.3V

Explanation: Not available for this question

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423
Q:

In Zener diode, for currents greater than the knee current, the v-i curve is almost

A) Almost a straight line parallel to y-axis B) Almost a straight line parallel to x-axis
C) Equally inclined to both the axes with a positive slope D) Equally inclined to both the axes with a negative slope
 
Answer & Explanation Answer: B) Almost a straight line parallel to x-axis

Explanation: Note that the curve is v-I curve and not an i-v curve.

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340
Q:

A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of R?p.

A) 625 ohm B) 1250 ohm
C) 2500 ohm D) 5000 ohm
 
Answer & Explanation Answer: C) 2500 ohm

Explanation: Not available for this question

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286
Q:

A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of gm.

A) 12mA/V B) 24 mA/V
C) 36 mA/V D) 48 mA/V
 
Answer & Explanation Answer: D) 48 mA/V

Explanation: Not available for this question

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270
Q:

Bridge rectifier is an alternative for

A) Bridge rectifier is an alternative for B) Peak rectifier
C) Half wave rectifier D) None of the mentioned
 
Answer & Explanation Answer: A) Bridge rectifier is an alternative for

Explanation: Bridge rectifier is a better alternative for a full wave rectifier.

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