Home
Class 12
PHYSICS
A solenoid with large number of turns is...

A solenoid with large number of turns is in a closed circuit and a short bar magnet is dropped through each with its length along the axis. State the acceleration of the falling magnet when it is :

a. Well above A b. At the end A
c. At the middle d. At the end B
e. Far away, down, from B

Text Solution

Verified by Experts

a. Acceleration due to gravity (g) b. Less than g by Lenz.s law.
c. Same as in (a) d. Less than g, by Lenz.s law.
e. Free from induction and hence `a=g`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ELECTROMAGNETIC INDUCTION

    NEW JOYTHI PUBLICATION|Exercise CONTINUOUS EVALUATION (ASSIGNMENTS)|2 Videos

  • ELECTROMAGNETIC INDUCTION

    NEW JOYTHI PUBLICATION|Exercise PREVIOUS YEAR QUESTIONS|2 Videos

  • ELECTROMAGNETIC INDUCTION

    NEW JOYTHI PUBLICATION|Exercise PRACTICE PROBLEMS FOR SELF ASSESSMENT|3 Videos

  • ELECTRIC CHARGES AND FIELDS

    NEW JOYTHI PUBLICATION|Exercise Competitive Exam Corner|20 Videos

  • ELECTROMAGNETIC WAVES

    NEW JOYTHI PUBLICATION|Exercise COMPETITIVE EXAM CORNER|16 Videos

Similar Questions

Explore conceptually related problems

Let the magnetic moment of a bar magnet be vec(p_(m)) whose mangetic length is d = 2l and pole strenght is q_(m) . Compute the magnetic moment of the bar magnet when it is cut into two pieces. (a) along its length (b) perpendicular to its length

You are given a solenoid of length 'l', number of turns per unit length 'n' and area of cross-section A. When a current 'I' passes through it, a. What is the total magnetic flux through the solenoid? b. What is the self inductance of the solenoid? c. How does the value of self inductance get affected if some material of high relative permeability is filled inside the solenoid?

The current in an ideal, long solenoid is varied at a uniform rate of 0.01 As^(-1). The solenoid has 2000 turns/m and its radius 6.0 cm. (a) Consider a circle of radius 1.0 cm inside the solenoid with its axis coinciding with the axis of the solenoid. write the change in the magnetic flux through this circle in 2.0 seconds. (b) find the electric field induced at a point on the circumference of the circle. (c) find the electric field induced at a point outside the solenoid at a distance 8.0cm from its axis.

A closely wound solenoid of 2000 turns and are of cross - section 1.6xx10^(-4)m^2 carrying a current of 4.0 A , is suspended through its centre allowing it to turn in a horizontal plane. a. What is the magnetic moment associated with the solenoid ? b. What is the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5xx10^(-2)T is set up at an angle of 30^@ with the axis of the solenoid ?

A string of length L fixed at both ends vibrates in its fundamental mode at a frequency v and a maximum amplitude A. (a) Find the wavelength and the wave number k. (b) Take the origin at one end of the string and the X-axis along the string. Take the Y-axis along the direction of the displacement. Take t = 0 at the instant when the middle point of the string passes through its mean position and is going towards the positive y-direction. Write the equation describing the standing wave.

An electron is released from the origin at a place where a uniform electric field E and a uniform magnetic field B exist along the negative y-axis and the nagative z-axis respectively. Find the displacement of the electron along the y-axis when its velocitybecomes perpendicular to the electric feld for the first time.

The rectangualr wire- frame, shown in has a width d, mass m, resistance R and a large length. A uniform magnetic field B exists to the left of the frame. A constant force F starts pushing the frame into the magnetic field at t =0. (a) Find the acceleration of the frame when its speed has increased to v. (b) Show that after some time the frame will move with a constant velocity till the whole frame enters into the magnetic field. find this velocity v_0 . (c) show that the velocity at tiem t is given by v= v_0(1 - e^(-Ft/mv_0) .

A tightly- wound, long solenoid is kept with its axis parallel to a large metal sheet carrying a surface current. The surface current through a width dl of the sheet is Kdl and the number of turns per unit length of the solenoid is n. The magnetic field near the centre of the solenoid is found to be zero. (a) find the current in the solenoid. (b) If the solenoid is rotated to make its axis perpendicular to the metal sheet, what would be the magnitude of the magnetic field near its centre?

A tightly- wound solenoid of radius a and length l has n turns per unit length. It carries an electric current i. Consider a length dx of the solenoid at a distance x from one end. This contains n dx turns and may be approximated as a circular current I n dx. (a) Write the magnetic field at the center of the solenoid due to this circular current. Integrate this expression under proper limits to find the magnetic field at the center of the solenoid. (b) Verify that if lgtgta , the field tends to (B=(mu_0ni) and if agtgt1 , the field tends to B= ((mu_0)nil/2a) . Interpret these results.

A 100 turn closely wound circular coil of radius 10 cm carries a current of 3.2 A. a. What is the field at the centre of the coil ? b. What is the magnetic moment of this coil ? The coil is placed in a vertical plane and is free to rotate about a horizontal axis which coincides with its diameter. A unifrom magnetic field of 2 T in the horizontal direction exists such that initially the axis of the coil is in the direction of the field. The coil rotates through an angle of 90^@ under the influence of the magnetic field . c. What are the magnitudes of the torques on the coil in the initial and final position ? d. What is the angular speed acqired by the coil when it has rotated by 90^(@) ? The moment of inertia of the coil is 0.1 kg m^2

Home
Profile