Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 11

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Electromagnets are made of soft iron because, soft iron has

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Important Questions on Magnetic Materials and Terrestrial Magnetism

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 1

In a permanent magnet at room temperature

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 2

Which of the following does not hold for magnetic field lines?

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 3

Two points $A$ and $B$ are situated perpendicular to the axis of $4 cm$ long bar magnet at distances $x$ and $3 x$ from its centre on opposite sides. The ratio of magnetic inductions at $A$ and $B$ will be equal to

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 4

A magnetic dipole is placed horizontally with the north pole pointing towards north. The horizontal component of earth's magnetic field is

20 μ T .

If the neutral point is found at a distance of

20 cm

in the plane bisecting the dipole then the magnetic moment of the dipole is
(Assume

μ_{0} = 4 π \times 10^{- 7}

S.I. units)

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 5

A bar magnet of magnetic moment

4.0 A m^{2}

is free to rotate about a vertical axis through its centre. The magnet is released from rest from East-West position. Kinetic energy of the magnet in North-South position will be

(B_{H} = 25 μ T)

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 6

At a certain place, the horizontal component of earth's magnetic field is

\frac{1}{\sqrt{3}}

times the vertical component. The angle of dip at that place is

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 7

The strength of the Earth’s magnetic field is

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Physics Crash Course NDA & NA EE>Chapter 20 - Magnetic Materials and Terrestrial Magnetism>Exercise 1>Q 8

A Jet plane is travelling west at

450

metres per second. If the horizontal component of Earth's magnetic field is

4 \times 10^{- 4}

Tesla and angle of dip is

30 °,

Then the vertical component is