Electricity and Magnetism Answers

Two parallel long wire carry i1 and i2 with i1 >i2 . When the current are in the same direction , the magnetic field at a point midway between the wires is 10 micro T. If the direction of i2 is reversed ,the field becomes 3micro T . The ratio of i1/i2 is (1)4. (2)3 (3)2. (4)1

An electron is moving in a uniform magnetic field B in a circular orbit of radius r. Suddenly the field is reduced to B/2.The radius of the path now becomes (1)2r (2)r/2 (3)r (4)4r

A long, straight wire of radius 5.0 mm carries a current of 20A. i) Calculate the
magnetic field at the surface of the wire, and ii) calculate the perpendicular distance,
from the axis of the wire, at which the magnitude of magnetic field will be half of
its value at the wire surface.

A long, straight wire of radius 5.0 mm carries a current of 20A. i) Calculate the
magnetic field at the surface of the wire, and ii) calculate the perpendicular distance,
from the axis of the wire, at which the magnitude of magnetic field will be half of
its value at the wire surface.

Two long, straight, parallel wires A and B, separated by a distance of 30 cm, carry
currents IA = 10A and IB = 30A. The currents in both the wires flow in the same
direction. Calculate the net magnetic field at the midpoint of the line joining the two
wires and perpendicular to them.

Two long, straight, parallel wires A and B, separated by a distance of 30 cm, carry currents IA = 10A and IB = 30A. The currents in both the wires flow in the same direction. Calculate the net magnetic field at the midpoint of the line joining the two wires and perpendicular to them

A long, straight wire of radius 5.0 mm carries a current of 20A. i) Calculate the magnetic field at the surface of the wire, and ii) calculate the perpendicular distance, from the axis of the wire, at which the magnitude of magnetic field will be half of its value at the wire surface.

1. A positively charged sphere is brought near to two neutral spheres. Indicate the charge distribution on both of the neutral spheres either in words or by drawing plus and minus signs within the neutral spheres.
2. A conducting sphere has a charge of +10 coulombs. A similar but neutral sphere is brought in contact with it.
a. What is the charge on each of the spheres once they touch?
b. Which particles are transferred and which way do they flow?
3. A conducting sphere A has a positive charge. Two neutral conducting spheres, B and C, are brought close to A. as shown. (Note that B and C are touching, unlike the case in question #1.)
ABC
In the end,
_____
a. B becomes positive and C negative
b. B becomes negative and C positive
c. both B and C remain neutral

A satellite explodes in the outer space and can be seen quickly from a spaceship in lunar orbit but the explosion cannot be heard, because ____.
A. There is no air on the moon
B. Light travels faster than sound
C. The light is reflected around the moon
D. Sound waves don't travel in straight lines

One mole of a gas occupies 22.4 liters at 0°C and 760 mm Hg. Calculate the pressure needed to compress 2.00 moles of oxygen into a 3.00-liter container maintained at 25°C.