Advertisements
Advertisements
प्रश्न
Write the formula for torque acting on rotating current carrying coil in terms of magnetic dipole moment, in vector form.
उत्तर
The formula for torque acting on the rotating current-carrying coil is:
τ = N I A B sin θ
τ = M B sin θ
In vector Form,
`vectau = vec M xx vec B`
where,
N = Number of turns,
I = Current in the coil,
A = Area of cross - section of coil,
B = Magnetic field.
M = Magnetic dipole moment.
APPEARS IN
संबंधित प्रश्न
Draw a neat and labelled diagram of suspended coil type moving coil galvanometer.
Will a current loop placed in a magnetic field always experience a zero force?
A circular loop of area 1 cm2, carrying a current of 10 A, is placed in a magnetic field of 0.1 T perpendicular to the plane of the loop. The torque on the loop due to the magnetic field is
A current loop of arbitrary shape lies in a uniform magnetic field B. Show that the net magnetic force acting on the loop is zero.
The figure shows a circular wire loop of radius a and carrying a current i, which is placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.
Suppose that the radius of cross-section of the wire used in the previous problem is r. Find the increase in the radius of the loop if the magnetic field is switched off. Young's modulus of the material of the wire is Y.
A rectangular loop of sides 20 cm and 10 cm carries a current of 5.0 A. A uniform magnetic field of magnitude 0.20 T exists parallel to the longer side of the loop. (a) What is the force acting on the loop? (b) What is the torque acting on the loop?
A circular loop carrying a current i is made of a wire of length L. A uniform magnetic field B exists parallel to the plane of the loop. (a) Find the torque on the loop. (b) If the same length of the wire is used to form a square loop, what would be the torque? Which is larger?
A square loop PQRS carrying a current of 6.0 A is placed near a long wire carrying 10 A as shown in figure. (a) Show that the magnetic force acting on the part PQ is equal and opposite to the part RS. (b) Find the magnetic force on the square loop.
A circular loop of one turn carries a current of 5.00 A. If the magnetic field B at the centre is 0.200 mT, find the radius of the loop.
A current-carrying circular coil of 100 turns and radius 5.0 cm produces a magnetic field of 6.0 × 10−5 T at its centre. Find the value of the current.
Derive an expression for the net torque on a rectangular current carrying loop placed in a uniform magnetic field with its rotational axis perpendicular to the field.
Derive the expression for the torque on a current-carrying coil in a magnetic field.
A 100 turn rectangular coil measuring 0.02 m x 0.06 m of an ammeter is in a magnetic field of induction 0.4 tesla. The torsional constant of the suspension fibre is 5 x 10-7 newton x metre/degree. The maximum reading of the ammeter corresponds to a deflection of the coil through 30°. If the magnetic field is radial, then the maximum current that can be measured with this ammeter is ____________.
If in a moving coil galvanometer, a current I produces a deflection `theta,` then ____________.
A rectangular coil has 200 turns each of area 50 cm2 . It is capable of rotation about an axis joining the mid points of two opposite sides. When a current of 10 A is passed through it while its plane is at right angles to a uniform magnetic field, it experiences a torque of 5 Nm. The magnetic field will be ____________.
Two galvanometers 'G1' and 'G2' require 2 mA and 3 mA respectively to produce the same deflection. Then _______.
If the net magnetic force acting on a loop is zero then ____________.
The magnetic field developed due to current carrying coil at its centre is 'B'. If the new coil of two turns is prepared from the above coil and same current is passed, then the magnetic field at the centre of the new coil will be ____________.
A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the
(a) total torque on the coil,
(b) total force on the coil,
(c) average force on each electron in the coil due to the magnetic field?
(The coil is made of copper wire of cross-sectional area 10–5 m2, and the free electron density in copper is given to be about 1029 m–3.)
When the plane of the coil is parallel to the field, torque will be ______
A current of 10 A is flowing in a wire of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform magnetic field of 2 T. The angle between the magnetic field and the direction of the current is ______.
A circular coil having N turns of radius R carrying a current I is used to produce a magnetic field B at its centre O.
If this coil is opened and rewound such that the radius of the newly formed coil is 2R, carrying the same current I, what will be the magnetic field at the centre O?
An electron moving along positive X axis with a velocity of 8 ×107ms-1 enters a region having uniform magnetic field B = 1.3 × 10-3 T along positive Y axis.
- Explain why the electron describes a circular path.
- Calculate the radius of the circular path described by the electron.
