Advertisements
Advertisements
Question
Answer the following question in detail.
A circular magnet is made with its north pole at the centre, separated from the surrounding circular south pole by an air gap. Draw the magnetic field lines in the gap.
Advertisements
Solution
For a circular magnet:
APPEARS IN
RELATED QUESTIONS
Magnetic lines of force are closed continuous curves.
Write any three properties of magnetic lines of force.
How are the magnetic field lines different from the electrostatic field lines?
A bar magnet of length 1 cm and cross-sectional area 1.0 cm2 produces a magnetic field of 1.5 × 10−4 T at a point in end-on position at a distance 15 cm away from the centre. (a) Find the magnetic moment M of the magnet. (b) Find the magnetisation I of the magnet. (c) Find the magnetic field B at the centre of the magnet.
Answer the following question.
Write the four important properties of the magnetic field lines due to a bar magnet.
An electron moves along +x direction. It enters into a region of uniform magnetic field `vec B` directed along −z direction as shown in fig. Draw the shape of the trajectory followed by the electron after entering the field.
A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to 4.5 × 10–2 J. What is the magnitude of magnetic moment of the magnet?
A closely wound solenoid of 800 turns and area of cross-section 2.5 × 10–4 m2 carries a current of 3.0 A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?
A closely wound solenoid of 2000 turns and area of cross-section 1.6 × 10–4 m2, carrying a current of 4.0 A, is suspended through its centre allowing it to turn in a horizontal plane.
- What is the magnetic moment associated with the solenoid?
- What is the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5 × 10–2 T is set up at an angle of 30° with the axis of the solenoid?
If the bar magnet is turned around by 180°, where will the new null points be located?
Which of the following statements about bar magnet is correct?
Magnetic field at far axial point due to solenoid as well as bar magnet varies ______.
According to the dipole analogy 1/ε0 corresponds to ______.
Four point masses, each of value m, are placed at the comers of a square ABCD of side L, the moment of inertia of this system about an axis through A and parallel to BD is ______.
The magnetic moment of atomic neon is equal to
When a current is passed through a tangent galvanometer, it gives a deflection of 30° for 60° correction, the current must be
When current is double deflection is also doubled in
A magnetic needle suspended freely orients itself:-
Magnetic dipole moment is a ______
A toroid of n turns, mean radius R and cross-sectional radius a carries current I. It is placed on a horizontal table taken as x-y plane. Its magnetic moment m ______.
Use (i) the Ampere’s law for H and (ii) continuity of lines of B, to conclude that inside a bar magnet, (a) lines of H run from the N pole to S pole, while (b) lines of B must run from the S pole to N pole.
Verify the Ampere’s law for magnetic field of a point dipole of dipole moment m = m`hatk`. Take C as the closed curve running clockwise along (i) the z-axis from z = a > 0 to z = R; (ii) along the quarter circle of radius R and centre at the origin, in the first quadrant of x-z plane; (iii) along the x-axis from x = R to x = a, and (iv) along the quarter circle of radius a and centre at the origin in the first quadrant of x-z plane.
A long straight wire of circular cross section of radius 'a' carries a steady current I. The current is uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point `a/2` above the surface of wire to that of a point `a/2` below its surface is ______.
In a uniform magnetic field of 0.049 T, a magnetic needle performs 20 complete oscillations in 5 seconds as shown. The moment of inertia of the needle is 9.8 × 10−6 kg m2. If the magnitude of magnetic moment of the needle is x × 10−5 Am2; then the value of ‘x’ is:
