### NEET Physics - New - Magnetism and Matter

#### Question - 1

An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 Am-1. The permeability of the material of the rod is: ________.

• A  2.4 p x 10-7 T mA-1
• B 2.4 p x 10-4 T mA-1
• C 8 x 10-5 T mA-1
• D ​​​​​​2.4 p x 10-5 T mA-1

#### Question - 2

A 800 turn coil of effective area 0.05 m2 is kept perpendicular to a magnetic field 5 x 10-5 T. When the plane of the coil is rotated by 90o around any of its coplanar axis in 0.1 s, the emf induced in the coil will be: ________ .

• A 0.2 V
• B 2 x 10-3 V
• C 0.02 V
• D 2 V

#### Question - 3

At a point A on the earth's surface the angle of dip, d = +25o. At a point B on the earth's surface the angle of dip, d = -25o. We can interpret that ______.

• A A is located in the southern hemisphere and B is located in the northern hemisphere.
• B A is located in the northern hemisphere and B is located in the southern hemisphere.
• C A and B are both located in the southern hemisphere.
• D A and B are both located in the northern hemisphere

#### Question - 4

A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 60o is W. Now the torque required to keep the magnet in this new position is _______.

• A $\frac{W}{\sqrt{3}}$
• B $\sqrt{3}W$
• C $\frac{\sqrt{3}W}{2}$
• D $\frac{2W}{\sqrt{3}}$

#### Question - 5

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnet dipole moment m. Which configuration has highest net magnetic dipole moment?

• A A
• B B
• C C
• D D

#### Question - 6

A bar magnet of magnetic moment M is placed at right angles to a magnetic induction B. If a force Fis experienced by each pole of the magnet, the length of the magnet will be _______.

• A F/MB
• B MB/F
• C BF/M
• D MF/B

#### Question - 7

A bar magnet of length '$\ell$ ', and magnetic dipole moment 'M' is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be _______.

• A $\frac{3}{\pi}M$
• B $\frac{2}{\pi}M$
• C $\frac{M}{2}$
• D M

#### Question - 8

A magnetic needle suspended parallel to a magnetic field requires $\sqrt{3}$J of work to turn it through 60o. The torque needed to maintain the needle in this position will be: _______.

• A 2$\sqrt{3}$ J
• B 3J
• C $\sqrt{3}$ J
• D $\frac{3}{2}J$

#### Question - 9

A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole, It: _________.

• A will become rigid showing no movement
• B will stay in any position
• C will stay in north-south direction only
• D will stay in east-west direction only

#### Question - 10

A short bar magnet of magnetic moment 0.4JT -1 is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the potential energy is ___________.

• A -0.64J
• B Zero
• C -0.0.82J
• D 0.064J