EC
Engineering Classroom
by Himalay Sen

Exams

Prepare for your next test with our collection of exam-based practice sets and question banks designed for effective assessment and revision.

সালের প্রশ্ন

Access past board exam questions organized by year and subject to help you understand patterns, improve preparation, and boost your exam performance.

MCQ
2541. As the temperature of a transistor goes up the base-emitter resistance-
decreases
increases
remains the same
none
ব্যাখ্যা: ব্যাখ্যা: As temperature increase, the thermal runway properly of transistor becomes more prominent and base-emitter resistance will decreases.
2543. 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
2545. 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
2552. In an LC oscillator, the frequency of oscillation is:
Proportional to LC
Proportional to square root of LC
Inversely proportional to the square root of LC
Independent of the value of LC
2553. 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
2555. A PN junction acts as a--
unidirectional switch
bidirectional switch
controlled switch
none of the above
ব্যাখ্যা: 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
2556. For highest power gain, one would use-- configuration.
CE
CB
CC
none of these
ব্যাখ্যা: 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
2557. Noise factor of a ideal amplifier is---
0dB
5dB
0.5dB
10dB
ব্যাখ্যা: ব্যাখ্যা: There is no noise in a ideal amplifier. So, noise factor is 0 dB