For a permanent magnetic material the residual induction and coercive field shou

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Question
For a permanent magnetic material
Options
A. the residual induction and coercive field should be large
B. the residual induction and coercive field should be small
C. area of hysteresis loop should be small
D. initial relative permeability should be high

Correct Answer

the residual induction and coercive field should be large

Explanation

Materials suitable for permanent magnet have large hysteresis loop.

Hence residual and coercive field are large.

Materials and Components problems

Search Results

1. If n denotes principal quantum number, the angular quantum number l = 0, 1... (n - 1).
Options
A. True
B. False

2. Above ferroelectric curie temperature, spontaneous polarization in ferroelectric materials becomes stronger.
Options
A. True
B. False

3. If e is the charge of an electron, R is the radius of its orbit and ? is the angular velocity of electron, the magnetic dipole moment ?_m of the orbit is |?_m| = e?R².
Options
A. True
B. False

4. Material which lack permanent magnetic dipoles are known as
Options
A. paramagnetic
B. diamagnetic
C. ferromagnetic
D. ferrimagnetic

5. The conductivity of intrinsic semiconductor is given by
Options
A. en_i(?_p - ?_n)
B. en_i(?_p + ?_n)
C. n_i(?_p + ?_n)
D. n_i(?_p?_n)

6. 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
Options
A. halved
B. kept the same
C. doubled
D. made 4 times

9. Assertion (A): At a temperature of 1000 K, thermionic emission current is about 0.1 A/cm² of surface.
Reason (R): Thermionic emission current is given by I_th = SA₀ T² e^-Ew/kT.
Options
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true

10. Assertion (A): From the slope of the line in Figure, we can find permanent dipole moment of the molecules.
Reason (R): Total polarization of a polyatomic gas is given by P = N(a_e + a_i + ?²_p / 3kT)E.
Options
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true

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