Timer 555 Applications Questions and Answers

The 555 timer can be employed in

1. A monostable multivibrator
2. A bistable multivibrator
3. An astable multivibrator Of these statements
Codes :

A.1 & 2 are correct.
B.1 & 3 are correct.
C.2 & 3 are correct.
D.1, 2 & 3 are correct.

Exam Year(s)

UGC NET - 2013,

Answer: B

The 555 timer can be wired as a monostable multivibrator, giving a single pulse of width 1.1RC for each trigger, and as an astable multivibrator, a free-running oscillator whose frequency depends on two resistors and a capacitor. The official key accepts only statements 1 and 3, as a bistable (flip-flop) operation is not a timing use of the device. The answer is 1 and 3 are correct.

Discuss in Forum

Direction for [ Question No: 2 To 2 ] :

Directions : The following items consists of two statements, one labelled the “Assertion (A)” and the other labelled the “Reason (R)”. You are to examine these two statements carefully and decide if the Assertion (A) and Reason (R) are individually true and if so, whether the reason is a correct explanation of the Assertion. Select your answer to these items using the codes given below and mark your answer accordingly.

Assertion (A) : A monostable multivibrator can be used to alter the pulse width of a repetitive pulse train.

Reason (R) : Monostable multivibrator has a single stable state.

A.Both (A) and (R) are true and (R) is the correct explanation of (A).
B.Both (A) and (R) are true, but (R) is not correct explanation of (A).
C.(A) is true, but (R) is false.
D.(A) is false, but (R) is true.

Exam Year(s)

UGC NET - 2014,

Answer: B

Both are true, but (R) is not the correct explanation of (A). A monostable multivibrator turns each trigger into an output pulse whose width is set by its own timing resistor and capacitor, so it can be used to alter the pulse width of a repetitive pulse train. That makes the assertion true.

It is also true that it has one stable state. But the single stable state only explains why it returns to rest after the pulse; the width is fixed by the RC time constant, so (R) does not explain (A). Hence option (B).

Discuss in Forum

Loading…

Topics

Other Subjects

Tags: Timer 555 Applications Questions and Answers || Timer 555 Applications MCQ Questions and Answers || Timer 555 Applications GK Questions and Answers || Timer 555 Applications GK MCQ Questions || Timer 555 Applications Multiple Choice Questions and Answers || Timer 555 Applications GK || GK on Timer 555 Applications || Linear Integrated Circuits Questions and Answers || Linear Integrated Circuits MCQ Questions and Answers || Linear Integrated Circuits GK Questions and Answers || GK on Linear Integrated Circuits

Timer 555 Applications Questions and Answers

Direction for [ Question No: 2 To 2 ] :

Topics

Other Subjects

About Us

Stay informed about all important Dates & Notifications