Q. A magnetic field exists around

View solution

Q. A conductor carries 10 A current in + x direction and is lying in a field having a flux density 0.2 T directed along + z direction. The magnitude of force per metre length and direction are

View solution

Q. The residual resistivity of a binary alloy at 0 K is

View solution

Q. The resistance of a photoconductor

View solution

Q. Assertion (A): Electron concentration n, hole concentration p and charge concentration ni are related by ni² = np.

Reason (R): p type semiconductor is obtained by adding trivalent impurity to intrinsic semiconductor.

View solution

Q. The temperature at which some materials become superconductors is called

View solution

Q. In Fermi-Dirac statistics, the probability of electron occupation of an energy level equal to Fermi level is

View solution

Q. The quantum numbers associated with electron motion are designed as

View solution

Q. The carrier mobility in a semiconductor is 0.4 m²/Vs. Its diffusion constant at 300 K will be (in m²/s)

View solution

Q. Which of these has lowest dielectric strength?

View solution

Q. The maximum temperature limit of class B insulation is

View solution

Q. Resistivity of metals consists of two parts, one part constant and the other temperature dependent.

View solution

Q. The number of valence electrons in germanium atom is

View solution

Q. Assertion (A): ∈₀ has the dimensions of farad per meter.

Reason (R): D = ∈₀∈ᵣ E.

View solution

Q. When temperature is more than ferromagnetic curie temperature, the behaviour of a ferromagnetic material is similar to that of paramagnetic material.

View solution

Q. As regards dielectric constant εr

View solution

Q. A parallel plate capacitor having C = 200 x 10¯¹² F has loss dielectric having tan δ = 4 x 10¯⁴. At an ac voltage of f = 10⁶ Hz and peak value 2 V, the dielectric losses are

View solution

Q. In ferromagnetic materials, the orientation between neighbouring permanent dipoles is parallel.

View solution

Q. Resistivity of copper is lower than that of nickel. When a small percentage of copper is added to nickel, the resistivity

View solution

Q. Lines of magnetic field attract each other.

View solution