Advertisements
Advertisements
प्रश्न
Solve the following problem.
A magnetic pole of a bar magnet with a pole strength of 100 A m is 20 cm away from the centre of a bar magnet. The bar magnet has a pole strength of 200 A m and has a length of 5 cm. If the magnetic pole is on the axis of the bar magnet, find the force on the magnetic pole.
Advertisements
उत्तर
Given that, (qm)1 = 200 Am and
(2l) = 5 cm = 5 × 10–2 m
∴ m = 200 × 5 × 10–2 = 10 Am2
For a bar magnet, magnetic dipole moment is,
m = qm (2l)
For a point on the axis of a bar magnet at distance, r = 20 cm = 0.2 m,
Ba = `μ_0/(4π)xx(2"m")/"r"^3`
= `10^-7xx(2xx10)/(0.2)^3`
= 0.25 × 10−3
= 2.5 × 10−4 Wb/m2
The force acting on the pole will be given by,
F = qm Ba = 100 × 2.5 × 10–4
= 2.5 × 10–2 N
The force acting on the magnetic pole due to the bar magnet is 2.5 × 10–2 N.
APPEARS IN
संबंधित प्रश्न
How are the magnetic field lines different from the electrostatic field lines?
An iron needle is attracted to the ends of a bar magnet but not to the middle region of the magnet. Is the material making up the ends of a bare magnet different from that of the middle region?
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 in brief.
What happens if a bar magnet is cut into two pieces transverse to its length/along its length?
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 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?
Which of the following statements about bar magnet is correct?
When iron filings are sprinkled on a sheet of glass placed over a short bar magnet then, the iron filings form a pattern suggesting that the magnet has ______.
According to the dipole analogy 1/ε0 corresponds to ______.
Magnetic moment for solenoid and corresponding bar magnet is ______.
The resistance of ideal voltmeter is
The magnetic moment of atomic neon is equal to
At a certain 100 p of reduces 0.0/57 m carrier a current of 2 amp. The magnetic field at the centre of the coop is [`mu_0 = 4pi xx 10^-7` wb/amp – m]
When current is double deflection is also doubled in
A magnetic needle suspended freely orients itself:-
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 ______.
A proton has spin and magnetic moment just like an electron. Why then its effect is neglected in magnetism of materials?
A ball of superconducting material is dipped in liquid nitrogen and placed near a bar magnet. (i) In which direction will it move? (ii) What will be the direction of it’s magnetic moment?
Suppose we want to verify the analogy between electrostatic and magnetostatic by an explicit experiment. Consider the motion of (i) electric dipole p in an electrostatic field E and (ii) magnetic dipole m in a magnetic field B. Write down a set of conditions on E, B, p, m so that the two motions are verified to be identical. (Assume identical initial conditions.)
A bar magnet of magnetic moment m and moment of inertia I (about centre, perpendicular to length) is cut into two equal pieces, perpendicular to length. Let T be the period of oscillations of the original magnet about an axis through the midpoint, perpendicular to length, in a magnetic field B. What would be the similar period T′ for each piece?
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 bar magnet is demagnetized by inserting it inside a solenoid of length 0.2 m, 100 turns, and carrying a current of 5.2 A. The coercivity of the bar magnet 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:
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:
