Advertisements
Advertisements
प्रश्न
Solve the following problem.
Two small and similar bar magnets have a magnetic dipole moment of 1.0 Am2 each. They are kept in a plane in such a way that their axes are perpendicular to each other. A line drawn through the axis of one magnet passes through the center of other magnet. If the distance between their centers is 2 m, find the magnitude of the magnetic field at the midpoint of the line joining their centers.
उत्तर
Let P be the midpoint of the line joining the centres of two bar magnets. As shown in figure, P is at the axis of one bar magnet and at the equator of another bar magnet. Thus, the magnetic field on the axis of the first bar magnet at distance of 1 m from the centre will be,
Ba = `μ_0/(4π)(2"m")/"r"^3`
= `10^-7xx(2xx1.0)/(1)^3`
= 2 × 10−7 Wb/m2
Magnetic field on the equator of second bar magnet will be,
Beq = `μ_0/(4π)("m")/"r"^3`
= `10^-7xx1.0/(1)^3`
= 1 × 10−7 Wb/m2
The net magnetic field at P,
Bnet = `sqrt("B"_"a"^2+"B"_"eq"^2)`
= `sqrt((2xx10^-7)^2+(1xx10^-7)^2)`
= `sqrt((10^-7)^2xx(4+1))`
= `sqrt(5)xx10^-7` Wb/m2
Magnitude of net magnetic field at midpoint of line will be `sqrt(5)xx10^-7` Wb/m2.
APPEARS IN
संबंधित प्रश्न
Magnetic lines of force are closed continuous curves.
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?
An electron moves along +x direction. It enters into a region of uniform magnetic field. `vecB` directed along –z direction as shown in fig. Draw the shape of the trajectory followed by the electron after entering the field.
Answer the following question in brief.
What happens if a bar magnet is cut into two pieces transverse to its length/along its length?
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.
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.
Answer the following question in detail.
Two bar magnets are placed on a horizontal surface. Draw magnetic lines around them. Mark the position of any neutral points (points where there is no resultant magnetic field) on your diagram.
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?
Which of the following statement about magnetic field lines is true?
Magnetic field at far axial point due to solenoid as well as bar magnet varies ______.
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
Magnetic dipole moment is a ______
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?
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.
There are two current carrying planar coils made each from identical wires of length L. C1 is circular (radius R) and C2 is square (side a). They are so constructed that they have same frequency of oscillation when they are placed in the same uniform B and carry the same current. Find a in terms of R.
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 ______.
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 ______.
