MCQ
2541. Noise factor of a ideal amplifier is---
ব্যাখ্যা: There is no noise in a ideal amplifier. So, noise factor is 0 dB
0dB
5dB
0.5dB
10dB
2542. As the temperature of a transistor goes up the base-emitter resistance-
ব্যাখ্যা: As temperature increase, the thermal runway properly of transistor becomes more prominent and base-emitter resistance will decreases.
decreases
increases
remains the same
none
2543. A zener diode is destroyed if it-
is forward biased
is reverse biased
carriers more than rated current
none of the above
2544. Which causes the barrier layer in a PN Junction--
doping
barrier potential
recombination
ions
2545. The purpose of a gate is to---
deliver molten metal into the mold cavity.
act as a reservoir for the molten metal.
feed the molten metal to the casting in order to compensate for the shrinkage.
deliver molten metal from pouring basin to gate
2546. The output frequency of a full wave rectifier is-
Same as the input frequency
One-half of the input frequency
Double of the input frequency
Independent of the input frequency
2547. If the ac supply is 50Hz, what will be the ripple frequency out of the full wave rectifier?
50Hz
100Hz
60Hz
20Hz
2548. A PN junction acts as a--
ব্যাখ্যা: The PN junction is conduct with forward bias only. It means they conduct in only one direction (Current flows from P to N) That's why PN Junction acts as unidirectional twitch
unidirectional switch
bidirectional switch
controlled switch
none of the above
2549. An SCR has-semiconductor layers.
Two
Three
Four
None of the above
2550. RC coupling is used for---amplification.
voltage
power
current
none
2551. The point of intersection of de and ac load lines is called-
saturation
operating
cut off
none of these
2552. The battery connections required to forword bias a pn junction are-
+ve terminal to p and -ve terminal to n
-ve terminal to pand+ ve terminal to n
-ve terminal to p and-ve terminal to n
+ve terminal to pand+ ve terminal to n
2553. The reverse current in a diode is of the order of—
KA
A
mA
uA
2554. A voltage divider consists of two 100k resistors and a 12V source. What will the output voltage be if a load resistor of 1 MQ is connected to the output?
0.57V
12V
5.7 V
6 V
2555. Approximately how many milliamperes of current flow through circuit with a 40V source and 6.8 ΚΩ of resistance?
27.2 mA
5.9 mA
59 mA
590 mA
2556. For highest power gain, one would use-- configuration.
ব্যাখ্যা: For highest power gain, CE configuration is used. In CE configuration, biasing capacitor is used to balance the operating point to obtain highest power gain
CE
CB
CC
none of these
2557. 1 db corresponds to --- changes in voltage level.
12%
20%
80%
26%
2558. In the normal operation of an SCR, anode is-- with respect to cathode.
at zero potential
negative
positive
none of the above
2559. An SCR has PN junctions.
Two
Four
Three
None of the above
2560. The most commonly used semiconductor is-
germanium
carbon
sulphur
silicon