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Worksheets

Magnets,Transfomr,circuit breaker

Total questions: 25

Worksheet time: 18mins

Name
Class
Date
1.

Which component opposes any change in current?

a)

Diode

b)

Resistor

c)

Inductor

d)

Capacitor

2.

Which factor determines the inductance value?

a)

Material of the coil

b)

Diameter of the coil

c)

Frequency of the current

d)

Current flow

3.

How much the impedence of the circuit which have R = 30 ohm and Xc= 40 ohm

a)

20

b)

30

c)

40

d)

50

4.

Find the total inductance value of 2 inductors 20H and 30 H are connected in series

a)

15

b)

30

c)

40

d)

50

5.

What is the name of effect of changing current in on coil,and induces an EMF in nearby coil?

a)

coupling

b)

Induction

c)

Self Induction

d)

Mutual Indution

6.

Which electrode controls brightness of the image on the screen of oscilloscope?

a)

Anode

b)

Cathod

c)

Control Grid

d)

Focussing electrode

7.

Which of the following is not a unit of flux?

a)

Maxwell

b)

Tesla

c)

Weber

d)

All of them

8.

Which property of capacitor stores electrical energy in Electro magnetic field?

a)

Dielectric

b)

Capacitance

c)

Stray capacitor

d)

Capcitive reactance

9.

Capacitor consist of two parallel

a)

Conductors

b)

Semi conductors

c)

Inductor

d)

Insulator

10.

The capcitor to be fully charged only after a period of more than

a)

Three time constant

b)

Two time constant

c)

Five time constant

d)

One time constant

11.

Example of diamagnetic materials

a)

Super condutors

b)

Transition metals

c)

Alkali metals

d)

Ferrite

12.

Example of para magnetic materials

a)

Super conductors

b)

Alkali metals

c)

Transition metals

d)

Ferrite

13.

Unit if magnetic flux density?

a)

Weber

b)

Maxwell

c)

Tesla

d)

W/m2

14.

ELCB works on the principle of

a)

Overload current

b)

short circuit

c)

Residual current

d)

Neutral current

15.

Which devices can be used as switch as well as protective devices?

a)

MCB

b)

ELCB

c)

Intermediate switch

d)

SPDT

16.

A 5F ,4.3 F and 0.6 F connected in parallel then find the total capacitance of the circuit?

a)

9.9

b)

.56

c)

9.3

d)

2.3

17.

Quality factor is also known as

a)

Voltage magnification

b)

Current magnification

c)

Resistance magnification

d)

Impedence

18.

The inductance of an iron coil decreases when

a)

Number of turns decreases

b)

The iron corr removed

c)

The length of the coil decreases

d)

None of the above

19.

If the current in one coil becomes steady,then the current in neighbouring coil is

a)

Zero

b)

Infinity

c)

Doubles

d)

Halved

20.

What is used as the electric material in high voltage transformer?

a)

Mica

b)

parfin

c)

Parcelain

d)

coiled paper

21.

Why the transformer core is made as thin lamination

a)

To maximize current

b)

To maximise voltage

c)

To minimize eddy current

d)

To minimize voltage

22.

ELCB are of

a)

two type

b)

one type

c)

three type

d)

none of these

23.

Gauss is the unit of

a)

Magnetic flux density

b)

Force

c)

Magnetic Field

d)

Power

24.

Whats if turns ratio of transformer?

a)

Ns/Np

b)

Np/Ns

c)

Vp/Vs

d)

Vs/Vp

25.

What if voltage ratio of transformer?

a)

Vp+Vs

b)

Vp/Vs

c)

Vs/Vp

d)

1/Vp