Magnetism and Matter  MCQs

MCQs of Magnetism and Matter

Showing 111 to 120 out of 145 Questions
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111.
An electron in an atom is revolving round the nucleus in radius 5.3 × 10-11 m, with a speed of 2 × 106 ms-1. The resultant orbital magnetic moment and angular momentum of the electron is _____ Take charge of electron = 1.6 × 10-19 C, mass of electron = 9.1 × 10-31 kg.
(a) 8.48 × 10-35 Am2, 9.65 × 10-24 Nms
(b) 8.48 × 10-24 Am2, 9.65 × 10-35 Nms
(c) 9.65 × 10-24 Am2, 8.48 × 10-35 Nms
(d) 8.48 × 10-24 Am2, 6.65 × 10-24 Nms
Answer:

Option (b)

112.
The magnetic field from a current carrying loop of diameter 1 cm is 10-4 T at 10 cm from the centre, along the axis of the loop. (a) Find the magnetic moment of the loop. (b) Find the magnetic field at 10 cm from the centre, along the equator of the loop. (Take μ0 = 4π × 10-7 Tm A-1)
(a) m = 0.5 Am2, B = 5 × 10-5 T
(b) m = 5.0 Am2, B = 0.5 × 10-5 T
(c) m = 0.5 Am2, B = 0.5 × 10-5 T
(d) m = 5.0 Am2, B = 5 × 10-5 T
Answer:

Option (a)

113.
A magnet in the form of a cylindrical rod has a length of 5 cm and a diameter of 2 cm. It has a uniform magnetization of 5 × 103 Am-1. Its net magnetic dipole moment is _____ .
(a) 7.85 × 10-2 JT-1
(b) 8.75 × 10-2 JT-1
(c) 5.78 × 10-2 JT-1
(d) 7.58 × 10-2 JT-1
Answer:

Option (a)

114.
An ionized gas consists of 5 × 1021 electrons/m3 and the same number of ions/m3. If the average electron kinetic energy is 6 × 10-20J, and an average ion kinetic energy is 8 × 10-21J. The magnetization of the gas when a magnetic field of 1.0 T is applied to the gas is _____
(a) 340 JT-1m-3
(b) 680 JT-1m-3
(c) 170 JT-1m-3
(d) 34 JT-1m-3
Answer:

Option (a)

115.
A closely wound solenoid of 6 cm, having 10 turns/cm and area of cross- section 3 × 10-4 m2 carries a current of 1.0 A. The maagnetic moment and the pole strength of the solenoid is _____ .
(a) 1.8 × 10-2 Am2, 0.3 Am
(b) 0.3 × 10-2 Am2, 1.8 Am
(c) 1.8 Am2, 0.3 × 10-2 Am
(d) 0.3 Am2, 1.8 × 10-2 Am
Answer:

Option (a)

116.
Which of the following is a stone of magnetite ?
(a) MnO2
(b) Na2CO3
(c) Fe3O4
(d) MgCl2
Answer:

Option (c)

117.
B2μ0 has the unit of _____
(a) energy
(b) energy density
(c) potential energy
(d) capacitance
Answer:

Option (b)

118.
Domain formation is the necessary feature of _____
(a) ferromagnetism
(b) paramagnetism
(c) diamagnetism
(d) All of the above
Answer:

Option (a)

119.
Magnetic susceptibility of vacuum is _____ .
(a) 0
(b) -1
(c) 1
(d) +∞
Answer:

Option (a)

120.
Among which the magnetic susceptibility does not depend on the temperature ?
(a) Diamagnetism
(b) Paramagnetism
(c) Ferromagnetism
(d) None of the above
Answer:

Option (a)

Showing 111 to 120 out of 145 Questions
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