Q. Ferroelectric materials are those which

View solution

Q. Assertion (A): Power loss in a conductor of resistance P = I²R.
Reason (R): When a conductor is carrying current with current density J as a result of applied field E, then heat developed/m³/ second = JE.

View solution

Q. Assertion (A): For Diamond, μᵣ = 1
Reason (R): Diamond is a diamagnetic material.

View solution

Q. For a paramagnetic material, susceptiblity increases with increasing temperature.

View solution

Q. Hydrogen is used in

View solution

Q. Assertion (A): Ferroelectric materials have spontaneous polarization.
Reason (R): Above curie temperature, ∈ = C/(T-ϴ) for ferro-electric materials.

View solution

Q. If e is the charge of an electron, R is the radius of its orbit and ω is the angular velocity of electron, the magnetic dipole moment μm of the orbit is |μm| = eωR².

View solution

Q. If a piece of wood is placed in a magnetic field

View solution

Q. The number of valence electrons in donor impurity are

View solution

Q. In a true valence crystal, the bonding between the atoms is accomplished by the sharing of valence electrons.

View solution

Q. Which of the following are donor impurities?

1. Gold
2. Phosphorus
3. Boron
4. Antimony
5. Arsenic
6. Induim

Select the correct answer using the following codes

View solution

Q. If n denotes principal quantum number, the angular quantum number l = 0, 1... (n - 1).

View solution

Q. Assertion (A): In a perfect capacitor, the current density is given by ω ∈₀E0∈'rcos(ωt + 90°), where ∈ᵣ' is real part of dielectric constant.
Reason (R): In a perfect capacitor, dielectric losses are zero.

View solution

Q. Assertion (A): For a solenoid having N turns, B = µ₀µᵣNI/L .
Reason (R): For all magnetic materials, B increases linearly with I.

View solution

Q. Assertion (A): If E is available energy state eV and EF is Fermi level, then probability of energy state E being occupied = 0.5.Reason (R): .

View solution

Q. A parallel plate capacitor has its length, width and separation doubled. It fringing effects are neglected, to keep the capacitance same, the dielectric constant must be

View solution

Q. Assertion (A): In imperfect capacitors, the current does not lead the applied ac voltage by 90°.
Reason (R): When subjected to ac fields, the dielectric constant can be expressed as ∈'r - j∈"r.

View solution

Q. In atomic physics, a state with l = 0 is called p state.

View solution

Q. If a sample of germanium and a sample of silicon have the same impurity density and are kept at room temperature

View solution

Q. When an electric field E is applied to solid and liquid insulating materials, the internal field Ei acting at the location of atom is such that

View solution