Electronics and Electrical Engineering interview Question and Answers for fresh engineers (Part 5)
In this topic we will find some question about unit cell in crystallization, circuit breaker and its properties, advantage of circuit breaker over fuse and switches, Arc voltage, re-striking voltage, recovery voltage.
Question: What is unit cell in crystallization?
Answer: The small cell which is most convenient in the crystal and carries all the properties and nature of the crystal is called unit cell. In the three dimensional system the repetitions of unit cell creates a whole structure of crystal.
Question: What is circuit breaker? What are the properties of circuit breaker?
Answer: A circuit breaker is a piece of equipment which can save devices from faults by using moving or fixed contacts, called as electrodes.
The main the properties of circuit breaker are,
· Make a circuit by remote control or manually under fault conditions.
· Under a fault condition break a circuit automatically.
· Make or break a circuit by remote control or manually under normal conditions.
Question: What is the advantage of circuit breaker over fuse and switches? What are the disadvantage of fuse and switches?
Answer: The fuse and switches are connected in series with the circuits. So the problems are as follows,
· The switches take quite sometimes for replacement and restore the power supply to the users, when it blows up.
· The fuse can not successfully block or interrupt a heavy current due to its series connectivity, which may damage the high capacity circuits.
Due to this disadvantages circuit breaker used over fuse and switches.
Question: What is Arc voltage?
Answer: During the arcing period the voltage that appears across the contacts of the circuit breaker is called arc voltage.
Question: What is re-striking voltage?
Answer: During the arcing period this is the transient voltage, which appears across the contacts at or near current zero is called as restriking voltage.
Question: What is recovery voltage?
Answer: After final arc extinction it is the normal arc frequency (50 Hz) root mean square (r.m.s) voltage that appears across the circuit breaker is called recovery voltage. The system voltage and recovery voltage are approximately equal.
-- - - - -- --- - -- - - -- - - - -- - -- - - - - - -- - - - -- - - - - - - - -
We will give more important questions and answers for electrical engineering interview very soon. Please subscribed to RSS feed or Email feed. We need your help for the betterment of the site. Please give comments and tell us what’s your opinions and needs from us. We will try to give your required things.
1 comment:
pls. sir , rply ans. for this question.
what is the difference between regulator & stabiliser ?
Post a Comment