4) In order to reduce hysteresis losses, the cores of electrical machines are generally made of :

tungsten steel

cast iron

high carbon steel

silicon steel

Answer is:

silicon steel

Whenever the flux linking through a coil or a circuit changes, e.m.f. is produced

The direction of dynamically induced e.m.f. can be determined by applying Fleming's right hand-rule

Coefficient of coupling or tightly coupled coils is zero

The coefficient of self inductance is proportional to the square of the number of turns on it

Answer is:

Joule's law

Coulomb's law

Faraday's law

Lenz's law

Answer is:

Lenz

Faraday

Maxwell

Ohm

Answer is:

removing gases from a material

removing impurities from magnetic materials

demagnetising a metallic part

demagnetising a magnet

Answer is: