Question 2 :
Alpha particles {tex} \left( \mathrm { m } = 6.7 \times 10 ^ { - 27 } \mathrm { kg } , \mathrm { q } = + 2 \mathrm { e } \right) {/tex} are accelerated from rest through a potential difference of 6.7 {tex} \mathrm { kV } {/tex}. Then, they enter a magnetic field {tex} \mathrm { B } = 0.2 \mathrm { T } {/tex} perpendicular to them direction of their motion. The radius of the path described by them is
Question 3 :
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 4 : 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 5 :
A short magnet oscillates in an oscillation magnetometer with a time period of 0.10{tex} \mathrm { s } {/tex} where the earth's horizontal magnetic field is 24{tex} \mu T {/tex} . A downward current of 18{tex} \mathrm { A } {/tex} is established in a vertical wire placed 20{tex} \mathrm { cm } {/tex} east of the magnet. Find the new time period.
Question 6 : The radius of the coil of a tangent galvanometer which has 10 turns is 0.1 m. The current required to produce a deflection of <img style='object-fit:contain' width='142' height='20' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea285ea3c680714de9a7d41"> is
Question 7 :
A coil in the shape of an equilateral triangle of side {tex} l {/tex} is suspended between the pole pieces of a permanent magnet such that {tex} \overrightarrow { \mathrm { B } } {/tex} is in the plane of the coil. If due to a current in the triangle a torque {tex} \tau {/tex} acts on it, the side {tex} l {/tex} of the triangle is
Question 8 :
A cable carrying a direct current is burried in a wall which stands in a north-south plane. A horizontal compass needle on the west side of the wall is found to point towards south instead of north. The coil is laid
Question 9 :
A loosely wound helix made of stiff wire is mounted vertically with the lower end just touching a dish of mercury. When a current from a battery is started in the coil through the mercury
Question 10 : An electron travelling with a speed u along the positive {tex} x {/tex} -axis enters into a region of magnetic field where {tex} B = - B _ { 0 } \hat { k } ( x > 0 ) . {/tex} It comes out of the region with speed {tex} \mathrm { v } {/tex} then<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60ef35e5db655bbf10a496">
Question 11 :
Proton, deuteron and alpha particle of same kinetic energy are moving in circular trajectories in a constant magnetic field. The radii of proton, deuteron and alpha particle are respectively {tex} r _ { p } , r _ { d } {/tex} and {tex} r _ { \alpha } {/tex} . Which one of the following relation is correct?
Question 12 :
The magnetic field of earth at the equator is approximately {tex}4 \times 10 ^ { - 5 } \mathrm { T } {/tex} . The radius of earth is {tex} 6.4 \times 10 ^ { 6 } \mathrm { m } . {/tex} Then the dipole moment of the earth will be nearly of the order of:
Question 13 :
A permanent magnet in the shape of a thin cylinder of length 10{tex} \mathrm { cm } {/tex} has magnetisation {tex} ( M ) = 10 ^ { 6 } \mathrm { A } \mathrm { m } ^ { - 1 } . {/tex} Its magnetization current {tex} I _ { M } {/tex} is
Question 14 :
A certain region has an electric field {tex} \vec{E} (2\hat{{ \mathrm { i } }} - 3\hat{ \mathrm { j } }){/tex} N / C and a uniform magnetic field {tex}\vec{B} (5\hat{{ \mathrm { i } }} + 3\hat{ \mathrm { j } } + 4\hat{ \mathrm { k } })T{/tex}. The force experienced by a charge 1C moving with velocity {tex}(\hat{{ \mathrm { i } }} + 2\hat{ \mathrm { j } }) ms^{–1}{/tex} is
Question 15 :
The AC voltage across a resistance can be measured using a :
Question 16 : An infinitely long straight conductor is bent into shape as shown in figure. It carries a current {tex}I{/tex} A. and the radius of circular loop is {tex} \mathrm { r } {/tex} metre. Then the magnetic induction at the centre of the circular loop is:<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e99a419debb574cf7016495"><br>
Question 17 :
The magnetic field due to a current carrying circular loop of radius 3{tex} \mathrm { cm } {/tex} at a point on the axis at a distance of 4{tex} \mathrm { cm } {/tex} from the centre is 54{tex} \mu \mathrm { T } {/tex} . What will be its value at the centre of loop?
Question 18 :
Two coaxial solenoids of different radius carry current {tex}I{/tex} in the same direction. {tex} \vec { F } _ { 1 } {/tex} be the magnetic force on the inner solenoid due to the outer one and {tex} \vec { F } _ { 2 } {/tex} be the magnetic force on the outer solenoid due to the inner one. Then:<br>
Question 19 :
A thin circular wire carrying a current {tex} I {/tex} has a magnetic moment {tex} M . {/tex} The shape of the wire is changed to a square and it carries the same current. It will have a magnetic moment
