MEDIUM
12th Assam Board
IMPORTANT
Earn 100
A circular coil of turns and radius carrying a current of is suspended vertically in a uniform horizontal magnetic field of magnitude . The field lines make an angle of with the normal of the coil. A counter torque is applied to prevent the coil from turning. Would your answer change, if the circular coil were replaced by a planar coil of some irregular shape that encloses the same area? (All other particulars are also unaltered.)
Important Questions on Moving Charges and Magnetism
HARD
12th Assam Board
IMPORTANT
Two concentric circular coils X and Y of radii and , respectively, lie in the same vertical plane containing the north to south direction. Coil X has turns and carries a current of ; coil Y has and carries a current of . The sense of the current in X is anticlockwise, and clockwise in Y, for an observer looking at the coils facing west. Give the magnitude and direction of the net magnetic field due to the coils at their centre.
MEDIUM
12th Assam Board
IMPORTANT
A magnetic field of () is required, which is uniform in a region of linear dimension about and area of cross-section about . The maximum current-carrying capacity of a given coil of wire is , and the number of turns per unit length that can be wound around a core is at most . Suggest some appropriate design particulars of a solenoid for the required purpose. Assume the core is not ferromagnetic.
MEDIUM
12th Assam Board
IMPORTANT
For a circular coil of radius R and N turns carrying current I; the magnitude of the magnetic field at a point on its axis at a distance from its centre is given by,
Show that this reduces to the familiar result for the field at the centre of the coil.
HARD
12th Assam Board
IMPORTANT
Consider two parallel coaxial circular coils of equal radius , and number of turns , carrying equal currents in the same direction, and separated by a distance . Show that the field on the axis around the midpoint between the coils is uniform over a distance that is small as compared to , and is given by,
MEDIUM
12th Assam Board
IMPORTANT
A toroid has a core (non-ferromagnetic) of inner radius and outer radius , around which turns of a wire are wound. If the current in the wire is , what is the magnetic field outside the toroid, inside the core of the toroid? Take,
EASY
12th Assam Board
IMPORTANT
A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?
EASY
12th Assam Board
IMPORTANT
A charged particle enters an environment of a strong and non-uniform magnetic field varying from point to point both in magnitude and direction and comes out of it following a complicated trajectory. Would its final speed equal the initial speed if it suffered no collisions with the environment?
MEDIUM
12th Assam Board
IMPORTANT
An electron is moving west to east enters a chamber having a uniform electrostatic field in the north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight-line path.
