Advertisements
Advertisements
प्रश्न
A short magnet produces a deflection of 37° in a deflection magnetometer in Tan-A position when placed at a separation of 10 cm from the needle. Find the ratio of the magnetic moment of the magnet to the earth's horizontal magnetic field.
Advertisements
उत्तर
Given :
Deflection in the magnetometer in the given position when placed in the magnetic field of a short magnet, θ = 37°
Separation between the magnet and the needle, d = 10 cm = 0.1 m
Let M be the magnetic moment of the magnet and `B_H` be Earth's horizontal magnetic field.
According to the magnetometer theory,
`M/B_H = (4pi)/u_0 (d^2 - l^2)^2/(2d) tan θ`
For the short magnet ,
`M/B_H = (4pi)/u_0 xx d^4/(2d) tan θ`
⇒`M/B_H = (4pi)/(4pi xx 10^-7) xx (0.1)^3/2 xx tan 37^circ`
⇒`M/B_H = 0.5 xx 0.75 xx 1 xx 10^4`
⇒`M/B_H = 3.75 xx 10^3 "A-m"^2"/"T`
APPEARS IN
संबंधित प्रश्न
What are permanent magnets? Give one example ?
Why should the material used for making permanent magnets have high coercivity?
Compare the direction of the magnetic field inside a solenoid with that of the field there if the solenoid is replaced by its equivalent combination of north pole and south pole.
If the current is doubled, the deflection is also doubled in
Consider the situation of the previous problem. The directions of the magnetic field due to the dipole are opposite at
(a) P1 and P2
(b) Q1 and Q2
(c) P1 and Q1
(d) P2 and Q2
To measure the magnetic moment of a bar magnet, one may use
(a) a tangent galvanometer
(b) a deflection galvanometer if the earth's horizontal field is known
(c) an oscillation magnetometer if the earth's horizontal field is known
(d) both deflection and oscillation magnetometer if the earth's horizontal field is not known
If the earth's magnetic field has a magnitude 3.4 × 10−5 T at the magnetic equator of the earth, what would be its value at the earth's geomagnetic poles?
The needle of a dip circle shows an apparent dip of 45° in a particular position and 53° when the circle is rotated through 90°. Find the true dip.
The magnetometer of the previous problem is used with the same magnet in Tan-B position. Where should the magnet be placed to produce a 37° deflection of the needle?
The combination of two bar magnets makes 10 oscillations per second in an oscillation magnetometer when like poles are tied together and 2 oscillations per second when unlike poles are tied together. Find the ratio of the magnetic moments of the magnets. Neglect any induced magnetism.
A short magnet oscillates in an oscillation magnetometer with a time period of 0.10 s where the earth's horizontal magnetic field is 24 μT. A downward current of 18 A is established in a vertical wire placed 20 cm east of the magnet. Find the new time period.
A bar magnet makes 40 oscillations per minute in an oscillation magnetometer. An identical magnet is demagnetized completely and is placed over the magnet in the magnetometer. Find the time taken for 40 oscillations by this combination. Neglect any induced magnetism.
Which property of soft iron makes it useful for preparing electromagnet?
Assertion: Electromagnetic are made of soft iron.
Reason: Coercivity of soft iron is small.
Which of the following is most suitable for the core of an electromagnet?
Which magnetic properties are desirable for making a permanent magnet?
