Q. 1 Bohr magneton = eh/(4πm) .

View solution

Q. An electron (charge -e) is rotating in a circular orbit of radius R, around a proton with charge +e at a constant angular velocity ω. The orbital magnetic dipole moment is

View solution

Q. The dielectrics having only one kind of atoms are known as elemental dielectrics.

View solution

Q. For a core having a relative permeability μᵣ, magnetic dipole moment per unit volume M and field strength H, the flux density B is

View solution

Q. The law that K/σT (where K is thermal conductivity, σ is electrical conductivity and T is absolute temperature) for all metals is equal to a universal constant is known as

View solution

Q. In elemental dielectrics, the orientation and ionic polarization are absent.

View solution

Q. In which of the following semiconductor are holes majority carriers

View solution

Q. The equation D = ∈₀∈ᵣ E refers only to isotropic materials.

View solution

Q. When a ferromagnetic substance is magnetised there are small changes in dimensions. This phenomenon is called

View solution

Q. Assertion (A): In some materials, Ɛᵣ is independent of temperature while in others, Ɛᵣ depends on temperature.

Reason (R): If permanent dipoles are absent, Ɛᵣ varies with temperature.

View solution

Q. An electron in a homogeneous magnetic field and having velocity perpendicular to the direction of field moves

View solution

Q. Spontaneous polarization occurs in ferroelectric materials.

View solution

Q. Lines of magnetic field cannot intersect.

View solution

Q. At T = 0, the resistivity of a perfect single crystal of a metal is

View solution

Q. In a polyatomic gas, the types of polarization which exist together are

View solution

Q. Assertion (A): Metals are better heat conductors than insulators.

Reason (R): If dT/dx is temperature gradient, Q is heat flow density and K is thermal conductivity, then Q = - K (dT/dx).

View solution

Q. In a virgin specimen of iron, the direction of spontaneous magnetisation varies from domain to domain.

View solution

Q. Which of the following is used in lightning arresters?

View solution

Q. High frequency inductors and capacitors are commonly plated with silver. The main purpose of this is to

View solution

Q. In its lowest state, the electron is bound to the field of proton by an energy equal to

View solution