Electricity and Magnetism Answers

An ideal step up transformer is primary coil has 500 turns and it’s secondary coil has 15,000 turns. The primary EMF is 120V. What is the EMF of the secondary?

Two circular loops A and B have their planes parallel to each other. Loop A has a current moving in the counterclockwise direction when viewed from above.

a. If the current in loop A decreases with time, what is the direction of the current in loop B? will the two loops attract or repel each other?

b. If the current in Loop A increases with time, what will be the direction of the current in Loop B? Will the two loops attract or repel each other?

An insulating sphere of radius 8.0 cm carries a uniform volume charge density

of 500 nC/m^3. What is the electric field in N/C at r = 3.0 cm?

Three point charges are arranged along the y-axis in a vacuum. The topmost charge bears a charge of -4.0 , the middle charge has a charge of 3.0 , and the bottom carries a charge of -7.0 . What is the magnitude and direction of the net electrostatic force that the middle charge experiences if top-middle is separated by 0.2 m of distance and middle-bottom is also separated by 0.2 m of distance?

Two tiny, identical metal balls carry charges of 6.0  and -14.0 , and are 4 cm apart from each other. What is the force of attraction between these balls?

You have an empty balikbayan box that you placed in a horizontal uniform electric field. What would be the electric flux through the top, left, and right sides of this box of side 1.2 m if the electric field of 7.0 N/C is directed to the right?

A flat surface of area 1.25 m2 is rotated through a uniform horizontal electric field of 5 N/C. What is the electric flux if the surface is (a) parallel and (b) perpendicular to the electric field?

At the three consecutive corners of a square, 10 cm on each side, are point charges 4 x 10^-6 C, 8 x 10^-6 C, and 12 x 10^-6 C, respectively. Find the E_P at the fourth corner of the square.

Assume that lightning strikes completely vertically and that a known current flows from the cloud into the ground for some time. We want to detect a lightning strike with the help of a coil that is connected directly to a voltmeter. Explain which phenomenon is responsible for lightning detection. Sketch the magnetic field of lightning and how the coil should be oriented for the effect to be strongest.

Four point charges arw equally separated by 1.00m in air as shown.If q1=3.0nC,q2=4.0nC,q3=2.0nC,q4=5.0nC,what is the electric field at a point halfway between q2 and q3?