Electrical Engineering Interview Questions and Answers
Question - 31 : - How Tube Light Circuit Is Connected And How It Works?
Answer - 31 : -
A choke is connected in one end of the tube light and a starter is in series with the circuit. When supply is provided ,the starter will interrupt the supply cycle of AC. Due to the sudden change of supply the chock will generate around 1000volts . This volt will capable of to break the electrons inside the tube to make electron flow. once the current passes through the tube the starter circuit will be out of part. now there is no change of supply causes choke voltage normalized and act as minimize the current.
Question - 32 : - What Is Marx Circuit?
Answer - 32 : -
It is used with generators for charging a number of capacitor in parallel and discharging them in series.It is used when voltage required for testing is higher than the available
Question - 33 : - What Is Encoder, How It Function?
Answer - 33 : -
An encoder is a device used to change a signal (such as a bitstream) or data into a code. The code may serve any of a number of purposes such as compressing information for transmission or storage, encrypting or adding redundancies to the input code, or translating from one code to another.
This is usually done by means of a programmed algorithm, especially if any part is digital, while most analog encoding is done with analog circuitry.
Question - 34 : - Why, When Birds Sit On Transmission Lines Or Current Wires Doesn’t Get Shock?
Answer - 34 : -
Its true that if birds touch the single one line (phase or neutral) they don’t get electrical shock… if birds touch 2 lines than the circuit is closed and they get electrical shock.. so if a human touch single one line(phase) then he doesn’t get shock if he is in the air (not touching – standing on the ground if he is standing on the ground then touching the line (phase) he will get a shock because the ground on what we standing is like line (ground bed – like neutral)? and in the most of electric lines the neutral is grounded..so that means that human who touch the line closes the circuit between phase and neutral.
Question - 35 : - What Is Meant By Armature Reaction?
Answer - 35 : -
The effect of armature flu to main flux is called armature reaction. The armature flux may support main flux or opposes main flux.
Question - 36 : - What Is Acsr Cable And Where We Use It?
Answer - 36 : -
ACSR means Aluminium conductor steel reinforced, this conductor is used in transmission & distribution.
Question - 37 : - What Is Vaccum Currcuit Breaker. define With Cause And Where Be Use It Device?
Answer - 37 : -
A breaker is normally used to break a ciruit. while breaking the circuit, the contact terminals will be separated. At the time of seperation an air gap is formed in between the terminals. Due to existing current flow the air in the gap is ionised and results in the arc. various mediums are used to quench this arc in respective CB’s. but in VCB the medium is vaccum gas. since the air in the CB is having vaccum pressure the arc formation is interrupted. VCB’s can be used upto kv.
Question - 38 : - What Will Happen When Power Factor Is Leading In Distribution Of Power?
Answer - 38 : -
If their is high power factor, i.e if the power factor is close to one:
- losses in form of heat will be reduced,
- cable becomes less bulky and easy to carry, and very cheap to afford, &
- it also reduces over heating of tranformers.
Question - 39 : - What Is 2 Phase Motor?
Answer - 39 : -
A two phase motor is a motor with the the starting winding and the running winding have a phase split.
e.g; ac servo motor. where the auxiliary winding and the control winding have a phase split of 90 degree.
Question - 40 : - What Is Power Factor? Whether It Should Be High Or Low? Why?
Answer - 40 : -
Power factor should be high in order to get smooth operation of the system. Low power factor means losses will be more.it is the ratio of true power to apparent power. it has to be ideally 1. if it is too low then cable over heating & equipment overloading will occur.
if it is greater than 1 then load will act as capacitor and starts feeding the source and will cause tripping.(if pf is poor ex: 0.17 to meet actual power load has to draw more current(V constant),result in more losses if pf is good.
ex: 0.95 to meet actual power load has to draw less current(V constant),result in less losses).