Question

The materials suitable for making electromagnets should have

(a) High retentivity and high coercivity

(b) Low retentivity and low coercivity

(c) High retentivity and low coercivity

(d) Low retentivity and high coercivity

Answer

(c) High retentivity and low coercivity

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Huygens principle of secondary waves:
Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr’s atomic model?

Assertion : Fax is a modulating and demodulating device.

Reason     : It is necessary for exact reproduction of a document.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If assertion is false but reason is true.

The human eye has a lens which has a

(a) Soft portion at its centre

(b) Hard surface

(c) Varying refractive index

(d) Constant refractive index

A concave mirror of focal length f, has formed the image of magnification m, the distance of the object from the mirror is :
Given below are the symbols of a few electronic components. Which of these components denote a variable inductor?

Light wave enters from medium 1 to medium 2.  Its velocity in 2nd medium is double from 1st.  For total internal reflection the angle of incidence must be greater than

(a) 30o

(b) 60 o

(c) 45 o

(d) 90 o

The sodium nucleus   contains

(a) 11 electrons

(b) 12 protons

(c) 23 protons

(d) 12 neutrons

In Young's double-slit experiments, a monochromatic light source is used. The shape of interference fringes produced on screen will be :
Which of the following is a wrong description of binding energy of a nucleus?
  1. It is the energy required to break a nucleus into its constituent nucleons.
  2. It is the energy made available when free nucleons combine to form a nucleus.
  3. It is the sum of the rest mass energies of its nucleons minus the rest mass energy of the nucleus.
  4. It is the sum of the kinetic energy of all the nucleons in the nucleus.