Home | | **High Voltage Engineering** | Important Short Questions and Answers: Generation of High Voltages and High Currents

High Voltage Engineering - Generation of High Voltages and High Currents - Important Short Questions and Answers: Generation of High Voltages and High Currents

**GENERATION OF HIGH VOLTAGES AND
CURRENTS**

**1. What is the necessity for generating high
voltages:**

Applications
like electric microscope, X rays, particle accelerators, Electro static
precipitators etc.

·
Testing power apparatuses.

·
Insulation testing.

**2. ****What are the various methods available for
generating High DC voltage?**

1. Half
& full wave rectifiers.

2. Voltage
multiplayer circuits.

Cockcraft
Walten Circuit

Delta-tran/Engi-tran

3. Van de graaff
generators.

4. Electro
static generators.

**3. ****What is the expression for average ripple in a
Cock- craft Walten voltage multipler.**

δ v = I
2n(2n+1)

ƒC 2

Where δ v
= total ripple

I = the
current

n =
number stages

f =
frequency of input voltage.

**4. What is the expression for regulation (drop in
voltage) Δv in a cock croft Walten method? **

Δv = 2/
ƒc [(2n3 /3) + (n2 /2) – (n/6)

Where Δv
= voltage drop

f =
frequency c = capacitance

n =
number of stages

**5. Give the expression for optimum number of stages
in a cock croft Walter voltage multiplier.**

Where V
max = Maximum of voltage

f =
frequency c = capacitance I = current

**6. State the principle of Van de Graaff generator ?**

Mechanical
energy is directly converted into electrostatic, electrical energy (without any
electromagnetic conversion, as in the case of an electromagnetic machine like
synchronous generator).

**7. How Impulse voltages are produced in the lab?**

Capacitors
previously charged to DC voltage is discharged into a wave shaping network (LR,
R1 R2, R3 or other combination) by closing a switch. This gives the desired
output (double exponential wave).

**8. What is the principle of Marx circuit.**

A bank of
capacitors are charged in parallel and then discharged in series into a wave
shaping network to produce a lighting impulse voltage, double exponential fast
rising & slow decaying voltage.

**9. How switching Impulse voltage can be produced in
the lab.**

1. Impulse
generator circuits can be used by suitably modifying the R_{1} & R_{2}.

2. Power Tr
or Testing Tr, excited by dc voltages giving oscillatory wave (Tesla tal)

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail

**Related Topics **

Copyright © 2018-2020 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.