Temporary magnets are used in which of the following ? Hoist. Generators. All of these. Motors. TRUE ANSWER : ? YOUR ANSWER : ?
The intensity of magnetization, M, of a ferro magnetic solid is independent of temperature. depends on method of heating. decreases with increasing temperature. increases with increasing temperature. TRUE ANSWER : ? YOUR ANSWER : ?
The number of rings in the Bohr model of any element is determined by what? Row number on periodic table. Atomic number. Atomic mass. Column number on periodic table. TRUE ANSWER : ? YOUR ANSWER : ?
Which of following material has least value of dielectric constant? Paper. Glass. Ceramics. Oil. TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following gives materials in order of decreasing values of permeability? Silver, copper, aluminium, iron. Cobalt, nickel, aluminium, iron. Permalloy, nickel, air, water. Pure iron, silicon iron, aluminium, bismuth. TRUE ANSWER : ? YOUR ANSWER : ?
Indicate which of following material does not retain magnetism permanently none of above. stainless steel. hardness steel. soft iron. TRUE ANSWER : ? YOUR ANSWER : ?
________ is the most detrimental impurity in the magnetic materials Sulphur. Carbon. Oxygen. Nitrogen. TRUE ANSWER : ? YOUR ANSWER : ?
In electrical machines the material preferred for pole shoes of electromagnets is aluminium. pure iron. copper. lead. TRUE ANSWER : ? YOUR ANSWER : ?
Almost the entire mass of an atom is concentrated in the neutrons. electrons. protons. nucleus. TRUE ANSWER : ? YOUR ANSWER : ?
What is the value of dielectric constant of air? Less than 1 1. none of these. 0. TRUE ANSWER : ? YOUR ANSWER : ?