NEET Physics: Questions 638 - 642 of 2099

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Question number: 638

» Magnetic Effects of Current and Magnetism » Hysteresis

MCQ▾

Question

Ferromagnetic material is heated above its Curie temperature, than which one is a correct statement?

Choices

Choice (4) Response
a.

Ferromagnetic material changes itself into diamagnetic material

b.

Ferromagnetic domains are perfectly arranged

c.

Ferromagnetic domains are not influenced

d.

Ferromagnetic domains becomes random

Question number: 639

» Magnetic Effects of Current and Magnetism » Para, Dia and Ferro-Magnetic Substances

MCQ▾

Question

A superconductor exhibits perfect

Choices

Choice (4) Response
a.

Diamagnetism

b.

Paramagnetic

c.

Ferrimagnetism

d.

Ferromagnetism

Question number: 640

» Magnetic Effects of Current and Magnetism » Electric Charge Moving in Magnetic Field

MCQ▾

Question

A straight horizontal copper wire carries a current i = 30 A. The linear mass density of the wire is 45 g/m. What is the magnitude of the magnetic field needed to balance its weight?

Choices

Choice (4) Response
a.

0 Gauss

b.

147 Gauss

c.

441 Gauss

d.

14.7 Gauss

Question number: 641

» Magnetic Effects of Current and Magnetism » Electric Charge Moving in Magnetic Field

MCQ▾

Question

A particle having charge q, mass m and kinetic energy E, enters a magnetic field B normally. It will oscillated with frequency equal to,

Choices

Choice (4) Response
a.

qB2πm

b.

mB2πq

c.

qE2πm

d.

qE2πB

Question number: 642

» Magnetic Effects of Current and Magnetism » Hysteresis

MCQ▾

Question

The mass of a specimen of a ferromagnetic material is 0.6 kg and its density is 7.8 x 10 3 kg/m 3. If the area of hysteresis loop of alternating magnetizing field of frequency 50Hz is 0.722 MKS units then the hysteresis loss per second will be

Choices

Choice (4) Response
a.

27.77 x 10 -4 Joule

b.

277.7 x 10 -6 Joule

c.

277.7 x 10 -5 Joule

d.

277.7 x 10 -4 Joule

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