A current of i ampere is flowing in an equilateral triangle of side a.The magnetic induction at the centroid will be.

ans: 9u_oi/2pia

An electron and a proton moving with the same speed enter the same magnetic field region at right angles to the direction of the field. For which of the two particles will the radius of the circular path be smaller.

what will be the magnatic field at the centre of an n -sided regular polygon if centre to the vertex distance is 'a' and the current is 'i' .... also find the limiting value of magnatic field as 'n' approaches a large value

A particle of charge per unit mass alpha is released from origin with a velocity V=VoI^{^} in a uniform magnetic field B= -Bok^{^}. If the particle passes through (0,y,0) then y is equal to

a particle of charge per unit mass 'a' is released frm origin with a velocity [vector v= v not * i cap] in a uniform magnetic field [B= - B not* k cap]. If the particle passes through (0,y,0) then y is equal to:

Correct answer: 2* v not / B not * a

A proton is accelerating in a cyclotron where the applied magnetic field is 2T . If the potential gap is effectively 100kV then how much revolutions the proton has to make between the dees to acquire a kinetic energy of 20MeV?

what are eddy current

a charged particle enters a magnetic field at right angles to the magnetic field . the field exists for a length equal to 1.5 times the radius of circular path of the particle . the particle will be deviated frm its path by

1. 90 deg

2. 1/ sin (2/3)

3. 30 deg

4. 180 deg

correct ans is 180deg Why????

The magnetic moment of a short bar magnet is 2Am². The magnetic field at a point 1m away from it in a direction making an angle 60 degree with its magnetic moment is

A particle of charge q and mass m starts moving from the origin under the action of an electric field (vector)E = E_oi and (vector)B = B_oi with velocity (vector)v = v_oj. The speed of the particle will become 2v_o after a time

a. t = 2mv_o/qE

b. t = 2Bq /mv_o

c. t = (3)^1/2Bq/mv_o

d. (3)^1/2mv_o/qE

what is the value of angle of dip at the magnetic poles of the earth??

two straight long conductors AOB and COD are perpendicular to each other and carry currents I1 and I2 respectively. find the magnitude of the magnetic field at a point P at a distance a from the point O in a direction perpendicular to the plane ABCD.

Two conducting rings of radii r and 2r move in opposite directions with velocities 2v and v respectively on a conducting surface . There is a uniform magnetic field of magnitude B perpendicular to plane of the rings. Find the potential difference between the highest points of the two rings.

a small current element Idl,with dl=2k^ mm and I = 2A is centered at the origin. Find magnetic feilds dB at the points:

1) on the x-axis at x=3 m

2) on the x-axis at x=-6 m

3) on the z-axis at z=3 m

1. d when the product I₁ I₂ is maintained at a constant positive value.
2. d when the product I₁ I₂ is maintained at a constant negative value.

A parallel plate capacitor of area 60 cm² and seperation 3 mm is charged initially to 90C. If the medium b/w the plate get slightly conducting at the plate loses the charge initially at the rate of 2.5 x 10^-8 C/s, then what is the magnetic field b/w the plate?

Ans in book is : zero

A long thin walled pipe of radius R carries a current I along its length The current density is uniform over the circumference of the pipe . The magnetic field at the centre of the pipe due to quarter portion of the pipe shown , is

A) μ_oI(2)^1/2/4²R

B) μ_oI/²R

C) 2μ_oI(2)^1/2/²R

D) none

Two parallel straight wires X and Y separated by a distance of 5 cm in air carry current of 10A and 5A respectively in opposite direction. Calculate the magnitude and direction of the force on a 20 cm length of the wire Y.

A particle of specific charge (q/m) α starts moving from the origin under the action of an electric field (vector)E = E_oi and magnetic field (vector)B = B_ok. Its velocity at (x_o,y_o,0) is (4i + 3j) . The value of x_o is

a. (13/2)αE_o/B_o

b. 16αB_o/E_o

c. 25/2αE_o

d. 5α/2B_o

Give the colour coding for the carbon resistor of 5 ohm having 10% tolerance. (1M)

PROVE THAT A CURRENT CARRYING SOLENOID BEHAVES AS A BAR MAGNET?

a straight wire of finite length carrying current I subtends an angle of 60degree at point P as shown. The magnetic field at P is.

A square loop of side a carries a current i .The magnetic field at the centre of loop is?

a dip circle is at right angle to the magnetic meridian. what will be the apparent dip?

A wire placed along east-west direction carries a current of 10 A from west to east direction.Determine the magnetic field due to a 1.8 cm piece of wire at a point 300 cm north-east from the piece.

Plzzzzzzzzzzzzzz answer to this question as soon as possible,this question is very very important for me!!!!!!.And plzzzz give the correct answer!!!!!.

In the circuit shown in the figure , if the potential at point A is taken as zero, the potential at point B is :

A 10g bullet having a charge of 4microC is fired at a speed of 270m/s in a horizontal direction. A vertical magnetic field of 500microT exists in the space. Find the deflection of the bullet due to the magnetic field as it travels through 100m. Make appropriate approximations.

1.Show through and example how ampere circuital law enablee an easy evaluation of the magnetic field where there is a symmetry in the system.

2.What does a toroid consist of?Show that for an ideal toroid of closely wound turns,the magnetic field i.iinside the toroid is constant and ii.in open space inside and exterior to toroid is 0?

A conducting rod of length l and mass m is moving down a inclined plane of inclination theta with constant velocity v . A current I is flowing in the conductor perpendicular and inwards. A vertically upward magnetic field exist in space. Magnitude of magnetic field . B is

Figure shows two current carrying wires 1 and 2 . find the magnitudes and directions of the magnetic feild at points P,Q and R.

20 cm

P Q R

1 2

A straight wire of lenght L is bnt into a semi-circular loop. Use Bio-Sawart law to deduce an expression for the magnetic field at its center due to the current I passing though it.