Emf

Question 1

If two force in a currentc carrying conductor move in the same direction

Answer 1

The force is attractive

Question 2

The device for converting electrical energy to mechanical energy

Answer 2

Electric motor

Question 3

The galvanometer works on the principle of

Answer 3

A current carrying conductor

Question 4

To increase the sensitivity of the galvanometer

Answer 4

Field is made stronger,number of turns increased,area of coil is increased,springs are made thinner

Question 5

Who discovered em.i

Answer 5

Micheal Faraday

Question 6

The induced emf depends in

Answer 6

Speed of the magnet/coil,number of turns,the presence of a soft iron core

Question 7

Faradays law is based on the concept that

Answer 7

Change in lines of force is proportional to rate s directly proportional to emf induced,the strength of the emf also proportional to the flux

Question 8

The magnetic flux depends on

Answer 8

(i)Magnetic field strength,number of turns,Area of each turn

Question 9

Generators are divided into 2

Answer 9

Ac generator,And D.C generator

Question 10

Ac current can be measured by

Answer 10

Hot wite ammeter,M.V.C galvanometer,M.I.Ammeter

Question 11

Ac can be made to produced dc by replacing

Answer 11

The two slips rings with a single split ring commutator

Question 12

The split ring is

Answer 12

A current reverser

Question 13

Mutual inductance is

Answer 13

Flow of inductance in a coil due to Ac

Question 14

Eddy currents reduce efficiency cause they

Answer 14

They consume power from the primary

Question 15

hysteresis loss

Answer 15

Wasted energy due to reversing the magnetization ofthe core

Question 16

Energy is lost in also

Answer 16

Leakage Of magnetic flux

Question 17

Heat is lost in a transformer by

Answer 17

Eddy current(solved by lamination),hysteresis loss,I^2R,Leakage of Magnetic flux

Question 18

Hysteresis loss is reduced by

Answer 18

The use of soft iron core

Question 19

Heat loss can be reduced by heat loss

Answer 19

Thick wires or low resistance coils

Question 20

Leakage is reduced by

Answer 20

Special coils of winding

Question 21

High tension transmission is known as

Answer 21

High voltage and low current

Question 22

Ac is preferred to DC in high tension transmission because

Answer 22

Ac can easily be stepped up while dc Volatage cannot

Question 23

Induction coil is used

Answer 23

In motor car and xray tubes

Question 24

____ changes the rapid speed in the

Answer 24

Make and break device

Question 25

Capacitor reduces

Answer 25

The effect of back emf induced in the induction coil