NEET Magnetic Effects of Current MCQs & PYQs

As shown in the figure, the radius of each of quarter circular arc is 2m. Find the magnetic moment of the given loop for the current in the loop :

A charge q coulomb moves in a circle with n revolutions per second and the radius of the circle is r metre. The magnetic field at the centre of the circle is :

A charged particle moves along a circle under the action of possible constant electric and magnetic fields. Which of the following are possible ?

Two particles Y and Z emitted by a radioactive source at P made tracks in a chamber as illustrated in the figure. A magnetic field acts downward into the paper. Careful measurements showed that both tracks were circular, the radius of Y track being half that of the Z track. Which one of the following statements is certainly true ?

A charged particle enters a uniform magnetic field with velocity vector at an angle of 45° with the magnetic field. The pitch of the helical path followed by the particle is p. The radius of circle of the helix will be :

A long straight, hollow, conductor (tube) carrying a current has two sections A and C of unequal cross sections joined by a conical section B. 1, 2 and 3 are points on a line parallel to the axis of the conductor. The magnetic fields at 1, 2 and 3 have magnitudes B1, B2 and B3. Then :

Figure shows three cases, in all cases the circular part has radius r and stragiht ones are infinitely long. For the same current the ratio of field B at center P in the three cases B1 : B2 : B3 is :

Find out magnetic dipole moment of given current loop.

Two parallel long wires carry currents i1 and i2 with i1 > i2. When the currents are in the same
direction, the magnetic field midway between the wires is 10μT. When the direction of i2 is reversed, it becomes 40μT. the ratio i1/i2 is :

The magnetic field at the centre of an equilateral triangular loop of side 2L and carrying a current i is :