Q. 254.0( 10 Votes )

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.)

Answer :

Given:


Number of turns, N = 20


Radius of coil, r = 10cm


Magnetic field strength = 0.10 T


Current in the coil = 5 A



a) The torque on the coil is zero because the magnetic field is uniform along the coil.


b) The total force on the coil is Zero due to uniform magnetic field.


c) Let average force on each electron in the coil due to magnetic field = F


Cross-sectional area of the wire, A = 10-5 m2


Free electron density or number of free electron per metre cube of copper, D = 1029


Charge in each electron = 1.6 × 1019 C


We know that,


…(1)


Where,


F = force due to magnetic field


B = Magnetic field strength


e = charge on electron


Vd = drift velocity of electron


Vd = I/ (NeA) …(2)


Where, I = current through the coil


N = Density of free electron


A = cross sectional area.


Putting values in equation (2)




Vd = 3.125 × 1043 ms-1


F = B × e × Vd …(3)


By putting the values of B, e and Vd in equation 3, we get,



F = 5 × 10-25 N


Hence, average force on each electron is 5 × 10-25 N.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Magnetic force on moving charge particle in magnetic fieldMagnetic force on moving charge particle in magnetic fieldMagnetic force on moving charge particle in magnetic field44 mins
Interactive Quiz on Magnetic field due to straight wire & circular loopInteractive Quiz on Magnetic field due to straight wire & circular loopInteractive Quiz on Magnetic field due to straight wire & circular loop41 mins
Master concept of Motional EMFMaster concept of Motional EMFMaster concept of Motional EMF51 mins
CyclotronCyclotronCyclotron37 mins
Equation of electric and magnetic fieldEquation of electric and magnetic fieldEquation of electric and magnetic field52 mins
Magnetic force on moving charge particle in magnetic field | QuizMagnetic force on moving charge particle in magnetic field | QuizMagnetic force on moving charge particle in magnetic field | Quiz32 mins
Magnetic field due to current carrying straight wireMagnetic field due to current carrying straight wireMagnetic field due to current carrying straight wire37 mins
Magnetic field due to current carrying circular loopMagnetic field due to current carrying circular loopMagnetic field due to current carrying circular loop36 mins
Interactive Quiz of Moving Charge and magnetismInteractive Quiz of Moving Charge and magnetismInteractive Quiz of Moving Charge and magnetism53 mins
Lorentz force & its applicationsLorentz force & its applicationsLorentz force & its applications33 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :