NEET Physics Moving Charges And Magnetism Class 12 Questions

As shown in the figure, a long straight conductor with semicircular arc of radius π/10 m is carrying current I = 3A. The magnitude of the magnetic field, at the center O of the arc is: (The permeability of the vacuum = 4π × 10⁻⁷ NA⁻²)

Which of the following statements are correct? (A) Electric monopoles do not exist whereas magnetic monopoles exist. (B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined. (C) Magnetic field lines are completely confined within a toroid. (D) Magnetic field lines inside a bar magnet are not parallel. (E) χ = -1 is the condition for a perfect diamagnetic material, where χ is its magnetic susceptibility.

An electron is moving along the positive x-axis. If the uniform magnetic field is applied parallel to the negative z-axis. Then A. The electron will experience magnetic force along positive y-axis B. The electron will experience magnetic force along negative y-axis C. The electron will not experience any force in magnetic field D. The electron will continue to move along the positive x-axis E. The electron will move along circular path in magnetic field Choose the correct answer from the options given below:

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

The figure given below shows a long straight solid wire of circular cross-section of radius 'a' carrying steady current I. The current I is uniformly distributed across its cross-section. The plot which correctly represents the variation of magnetic field (B) with distance (r) from the axis of the conductor in the region is:

A tightly wound 100 turns coil of radius 10 cm carries a current of 7 Å. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as 4π×10⁻⁷ SI units):

A very long conducting wire is bent in a semi-circular shape from <em>A</em> to <em>B</em> as shown in figure. The magnetic field at point <em>P</em> for steady current configuration is given by:

Given below are two statements: Statement I: Biot-Savart’s law gives us the expression for the magnetic field strength of an infinitesimal current element (Idl) of a current carrying conductor only. Statement II: Biot-Savart’s law is analogous to Coulomb’s inverse square law of charge q, with the former being related to the field produced by a scalar source, Idl while the latter being produced by a vector source, q. In light of above statements choose the most appropriate answer from the options given below:

A long solenoid of radius 1 mm has 100 turns per mm. If a current flows in the solenoid, the magnetic field strength at the centre of the solenoid is:

From Ampere’s circuital law for a long straight wire of circular cross-section carrying a steady current, the variation of magnetic field in the inside and outside region of the wire is:

An infinitely long straight conductor carries a current of 5 Å as shown. An electron is moving with a speed of 10⁵ m/s parallel to the conductor. The perpendicular distance between the electron and the conductor is 20 cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant.

A thick current carrying cable of radius 'R' carries current 'I' uniformly distributed across its cross-section. The variation of magnetic field B(r) due to the cable with the distance 'r' from the axis of the cable is represented by :

In the product \( \vec{F} = q (\vec{v} \times \vec{B}) \) = \( q \times (\hat{i} B_{i} + \hat{j} B_{j} + \hat{k} B_{0}) \) For q = 1 and \( \vec{v} = 2 \hat{i} + 4 \hat{j} + 6 \hat{k} \) and \( \vec{F} = 4 \hat{i} - 20 \hat{j} + 12 \hat{k} \) What will be the complete expression for \( \vec{B} \) ?

A cylindrical conductor of radius R is carrying a constant current. The plot of the magnitude of the magnetic field, B, with the distance, d, from the centre of the conductor, is correctly represented by the figure:

A metallic rod of mass per unit length 0.5 kg m⁻¹ is lying horizontally on a smooth inclined plane which makes an angle of 30° with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is

An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current ‘I’ along the same direction is shown in figure. Magnitude of force per unit length on the middle wire ‘B’ is given by

If θ₁ and θ₂ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip δ is given by

A long straight wire of radius a carries a steady current I. The current is uniformly distributed over its cross-section. The ratio of the magnetic fields B and B' at radial distances 2a and 2a respectively, from the axis of the wire is

A square loop ABCD carrying a current i, is placed near and coplanar with a long straight conductor XY carrying a current I, the net force on the loop will be

A wire carrying current I has the shape as shown in adjoining figure. Linear parts of the wire are very long and parallel to X⁻axis while semicircular portion of radius R is lying in Y⁻Z plane. Magnetic field at point O is

The magnetic field inside a long solenoid is given by B = μ₀ni, where n is the number of turns per unit length and i is the current. If the solenoid is bent into a circle, the magnetic field at the center of the circle is:

An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude

Two identical long conducting wires AOB and COD are placed at right angles to each other, with one above other such that O is the common point for the two. The wires carry I₁ and I₂ currents, respectively. Point P is lying at distance d from O along a direction perpendicular to the plane containing the wires. The magnetic field at the point P will be

A long straight wire carries a certain current and produces a magnetic field 2 × 10⁻⁴ Weber/m² perpendicular distance of 5 cm from the wire. An electron situated at 5 cm from the wire moves with a velocity 10⁷ m/s towards the wire along perpendicular to it. The force experienced by the electron will be (charge on electron 1.6 × 10⁻¹⁹ C):

A circular coil ABCD carrying a current 'I' is placed in a uniform magnetic field. If the magnetic force on the segment AB is F, the force on the remaining segment BCDA is: