8/2/2019 Question and Answars From Basic of Electrical Engineering

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S. No. Questions Answers

1 When electron are moving from

the left to right, then How

current direction is from Right

to the left.

When electron moved from left to right, this is due to

potential applied, + at right side and negative at left

side, then due to potential difference current flow from

right to left. This happen in DC circuit. In A.C. voltage

applied is alternating in nature therefore current is alsoalternating in the nature. If sinusoidal A.C. Voltage is

applied then current is also sinusoidal. If Circuit is pure

resistive circuit, the current shall be in phase to the

applied voltage. As electrons vacate their atoms

during electron current flow, positively charged

atoms (holes) result. The flow of electrons in one

direction causes a flow of positive charges. The

direction of the positive charges is in the opposite

direction of the electron flow. This flow of positive

charges is known as conventional current.

2 What is Coulombs law ofelectrostatic charges

Coulombs law of electrostatic charges states that forcesof attraction or repulsion between the charged particle

is proportional to product of charges between then and

inversely proportional to distance between them.

F=Kq1.q2/d2

F= Force of attraction or repulsion between charges

particles in Newton

q1, q2= Charge on particles in coulombs

d= distance between charge particle in meters

K= Constant of proportionality in Coulombs2/Newtom-

m2

3 What is the first law ofElectrostatics

Like charges repel each other and unlike charges attracteach other.

4 What is potential When an electric charge is placed into electrostatic field,

then due electrostatic charge particle moves into the

field due to force of attraction or repulsion. Thus ability

to do work is called potential, if one charge is different

from others, and then there exists potential difference

between the charge particles. The sum of the Potential

difference of all the charge particle in the electrostatic

field is Electromotive force.

5 What is the atomic number of

Copper, silver, gold, aluminiumand ferrous (iron).

6 Give the specification ETP

copper bus bar to be used for

the bus bar work

7 Give the specification of

Aluminium bus bar (Two

channel welded together)

8 Specify the silver faced joints

9 Describe the use of gold in the

electrical industry.

10 What is inductance Inductance is defined as ability of coil to store energy,induce voltage in itself, and opposes the current flowing

8/2/2019 Question and Answars From Basic of Electrical Engineering

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through it. One hennery is the amount of inductance

that permits, one volt to be induce, when current

through coil changes at the rate of one ampere per

second. V= -L di/dt, where negative charge indicates that

voltage induce opposes the very cause rate of change of

current which has produced voltage.11 What is capacitance Capacitance is defined as ability to store electric charge,

capacitance is equal to amount of charge that can be

stored in a device or capacitor divided by Voltage across

it. C=Q/V

12 What are the various methods

of producing electricity

Following methods are used to produce voltage:-

Electrochemistry

Static electricity

Piezo electric effect

Magnetic induction

Thermo electricity

Thermionic emissionPhoto-electric effect