Electricity and Magnetism Answers

Three point charges q1, q2 and q3 are located at the corners of an equilateral triangle with sides of 10 cm. The electrical forces between them are F12= 5.4 N (attractive), F13= 15 N (repulsive) and F23= 9 N (attractive). Given that q1 is negative, what are the values of q2 and q3?

(Answer: q2= 1.89 μC and q3= -5.28 μC)

Two long parallel wire are 10cm carrying a current of 6A and 4A. Calculate the force of acting on a 100cm length of

Find the total charge of a cylinder of Radius R and Length L, carrying a charge density that is proportional to the distance from its axis.

Spheres A and B have the same initial positive charge qO.The magnitude of the repulsive electric force between the two spheres is 14.4 N when separated by a distance of 0.03 m.

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a) Find the initial q0

b)The spheres are then allowed to touch each other and then separated.Find the electric force between them if the radius of sphere A is three times that of sphere B.

Four equal-magnitude point charges (3.0 C) are placed at the corners of a square that is 40 cm on a side. Two, diagonally opposite each other, are positive, and the other two are negative. Find the force on either negative charge.

a) A +100-μC charge produces 1.5 T field 2 cm from the charge. Determine the magnitude of velocity of the charge. b) What magnetic field is produced by a charge twice that in part a) 4 cm away from it?

Derive the value of flux density at the specified point along the axis due to circular coil carrying current.

Consider three point charges q1= 5.0 μC , q2 = -2.0 μC and q3 = 5.0 μC, located at the corners of a triangle which has a coordinate of (0, 0) , (0, a) and (a, a) respectively. If a = 0.10 m, find

 a) the resultant force on q3.

 b) the magnitude and the direction of the resultant force on q3 

A solid copper sphere has a net positive charge. The charge is distributed uniformly over the surface of the sphere, and the electric field inside the sphere is zero. Then a negative point charge outside the sphere is brought close to the surface of the sphere. Is all the net charge on the sphere still on its surface? If so, is this charge still distributed uniformly over the surface? If it is not uniform, how is it distributed? Is the electric field inside the sphere still zero? In each case justify your answers.

A solenoid has 2000 turns on its 40cm length. What is the magnetic field intensity at its centre if it carries a current of 5A