Question 1 :
A thin bar magnet of length 2{tex} \ell {/tex} and breadth 2 b pole strength m and magnetic moment {tex} \mathrm { M } {/tex} is divided into four equal parts with length and breadth of each part being half of original magnet. Then, the magnetic moment of each part is

Question 2 :
A uniform magnetic field acts at right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius <img style='object-fit:contain' width=31 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bf3727ce131ff7c08b47"> . If the speed of the electrons is doubled, then the radius of the circular path will be

Question 3 :
Keeping dissimilar poles of two magnets of equal pole strength and length same side, their time period will be

Question 4 :
On applying an external magnetic field, to a ferromagnetic substance domains

Question 5 :
If two streams of protons move parallel to each other in the same direction, then they

Question 6 :
If a bar magnet of length <i>l </i>and cross-sectional area<i> A </i>is cut into two equal parts as shown in figure, then the pole strength of each pole becomes<br> <img style='object-fit:contain' width='261' height='181' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea2861d3c680714de9a7e23">

Question 7 :
The coil of a moving coil galvanometer is wound over a metal frame in order to

Question 8 :
The strength of the magnetic field around a long straight wire, carrying current, is

Question 11 :
In a current carrying long solenoid, the field produced does not depend upon

Question 12 :
To shield an instrument from external magnetic field, it is placed inside a cabin made of

Question 13 :
If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be

Question 14 :
An electron and a proton are projected at right angles to a uniform magnetic field with the same kinetic energy. Then

Question 15 :
An electron enters a magnetic field whose direction is perpendicular to the velocity of the electron. Then

Question 16 :
A magnet of length 14 cm and magnetic moment <i>M</i> is broken into two parts of length 6 cm and 8 cm. They are put at a right angle to each other with opposite poles together. The magnetic moment of the combination is

Question 17 :
The ultimate individual unit of magnetism is any magnet is called

Question 18 :
Two identical thin bar magnets each of length {tex} \ell {/tex} and pole strength m are placed at right angles to each other, with north pole of one touching south pole of the other, then the magnetic moment of the system is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60ef4ad3eb695bc07eb4f3"><br>

Question 20 :
A tangent galvanometer is connected directly to an ideal battery. If the number of turns in the coil is doubled, the deflection will

Question 21 :
A long straight wire along the z-axis carries a current I in the negative z direction. The magnetic vector field {tex} \overrightarrow { \mathrm { B } } {/tex} at a point having coordinates {tex} ( \mathrm { x } , \mathrm { y } ) {/tex} in the {tex} \mathrm { z } = 0 {/tex} plane is

Question 23 :
A dip needle which is free to move in a vertical plane perpendicular to magnetic meridian will remain

Question 25 :
The radius of the path of an electron moving at a speed of <img style='object-fit:contain' width=77 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1c0ac27ce131ff7c0922a"> perpendicular to a magnetic field 5 <img style='object-fit:contain' width=56 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1c0ac27ce131ff7c0922b"> is nearly

Question 26 :
A long, straight, solid metal wire of radius 2 mm carries a current uniformly distributed over its circular cross-section. The magnetic field induction at a distance 2 mm from its axis is <img style='object-fit:contain' width=10 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bf2027ce131ff7c08aca"> . Then the magnetic field induction at distance 1 mm from axis will be

Question 27 :
Proton and <img style='object-fit:contain' width=23 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bfb91ac76a0b860fe87c"> particle are projected perpendicularly in a magnetic field, if both move in a circular path with same speed. Then ratio of their radii is

Question 28 :
The points <img style='object-fit:contain' width='49' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea286a03c680714de9a7fcc"> are situated perpendicular to the axis of 2 cm long bar magnet at large distances <img style='object-fit:contain' width='8' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea286123c680714de9a7de1"> and 3 <img style='object-fit:contain' width='8' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea286123c680714de9a7de1"> from the centre on opposite sides. The ratio of magnetic fields at <img style='object-fit:contain' width='49' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea286a03c680714de9a7fcc"> will be approximately equal to

Question 32 :
Two infinitely long parallel wires carry equal current in same direction. The magnetic field at a mid point in between the two wires is

Question 33 :
A magnet is placed on a paper in a horizontal plane for locating neutral points. <img style='object-fit:contain' width='9' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea286113c680714de9a7dd7"> dip needle placed at the neutral point will be horizontal at the

Question 35 :
The velocity of two <img style='object-fit:contain' width=9 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bfaa27ce131ff7c08d52"> -particles <img style='object-fit:contain' width=51 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea1bf281ac76a0b860fe5a9"> in a uniform magnetic field is in the ratio of 1 : 3. They move in different circular orbits in the magnetic field. The ratio of radius of curvatures of their paths is

Question 36 :
A moving charge will gain energy due to the application of

Question 37 :
In a cyclotron, the angular frequency of a charged particle is independent of

Question 38 :
The magnetising field required to be applied in opposite direction to reduce residual magnetism to zero is called

Question 40 :
Four wires, each of length 2.0 m, are bent into four loops P,Q, R and S and then suspended in a uniform magnetic field. If the same current is passed in each, then the torque will be maximum on the loop <br><br><img style='object-fit:contain' src="https://data-screenshots.sgp1.digitaloceanspaces.com/5d60f87cca41306d7a3240ed.jpg" />

Question 41 :
When a charged particle moving with velocity is subjected to a magnetic field of induction {tex} \overrightarrow { \mathrm { B } } , {/tex} the force on it is non- zero. This implies that

Question 42 :
In sum and difference method vibration magnetometer, the time period is more if

Question 43 :
A compass needle whose magnetic moment is {tex} 60 \mathrm { Am } ^ { 2 } , {/tex} is directed towards geographical north at any place experiencing moment of force of {tex} 1.2 \times 10 ^ { - 3 } \mathrm { Nm } {/tex} . At that place the horizontal component of earth field is 40{tex} \mathrm { micro } \mathrm { W } / \mathrm { m } ^ { 2 } {/tex} . What is the value of dip angle at that place?

Question 44 :
Torques {tex} \tau _ { 1 } {/tex} and {tex} \tau _ { 2 } {/tex} are required for a magnetic needle to remain perpendicular to the magnetic fields at two different places. The magnetic fields at those places are {tex} \mathrm { B } _ { 1 } {/tex} and {tex} \mathrm { B } _ { 2 } {/tex} respectively; then ratio {tex} \frac { \mathrm { B } _ { 1 } } { \mathrm { B } _ { 2 } } {/tex} is

Question 45 :
In the given figure, what is the magnetic field induction at point {tex} \mathrm { O } ? {/tex}<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e99a40fdebb574cf701648f"><br>

Question 47 :
A dip needle lies initially in the magnetic meridian when it shows an angle of {tex} \operatorname { dip } \theta {/tex} at a place. The dip circle is rotated through an angle {tex} x {/tex} in the horizontal plane and then it shows an angle of {tex} \operatorname { dip } \theta ^ { \prime } {/tex} . Then {tex} \frac { \tan \theta ^ { \prime } } { \tan \theta } {/tex} is

Question 48 :
In a vibration magnetometer, the time period of a bar magnet oscillating in horizontal component of earth's magnetic field is 2 sec. When a magnet is brought near and parallel to it, the time period reduces to 1 sec. The ratio {tex} \mathrm { H } / \mathrm { F } {/tex} of the horizontal component {tex} \mathrm { H } {/tex} and the field {tex} \mathrm { F } {/tex} due to magnet will be