Electricity and Magnetism Answers

The series combination of 5 F and 20 F capacitors is connected in parallel to 4 F capacitor. What is the total charge stored in the combination of capacitors when connected to 100V

The series combination of 5 F and 20 F capacitors is connected in parallel to 4 F capacitor. What is the equivalent capacitance

Charges of q+ and q- at the two vertices of an equilateral triangle. What can be said of the electric field E and potential V at the unoccupied vertex?

1. A long, straight conductor carries a current of 200 A. At what distance from the conductor is the magnetic field

caused by the current equal to the Earth’s magnetic field?

2. A power cable contains two long parallel conductors placed 1.5 cm apart. It carries a current of 125 A to a 40 hp

electric motor. Find the force exerted on a 2.0 m length of one conductor?

3. A coil used to produce a magnetic field for an electron beam experiment has a radius of 15 cm and has 300

turns. What current is needed to produce a magnetic field of 5.0 x 10-3 T?

A circular coil of wire 0.0275 m in radius, having 25 turns, lies in a horizontal plane. It carries a current of 3.00 A in a

counterclockwise rotation when viewed from above. The coil is in the magnetic field directed towards the right with a

magnitude of 1.20 T. Find the magnetic moment and the torque on the coil.

1. A beam of protons, each with charge 𝑞 ≅ 1.60 × 10−19𝐶, is moving at 4.50 × 105𝑚/𝑠 through a uniform magnetic

field with magnitude 0.60 T. The direction of motion of the protons is to the right, and the magnetic field direction is downward-right, at an angle of 𝜃 = 𝜋 6 𝑟𝑎𝑑𝑖𝑎𝑛𝑠 from the proton direction. Find the magnetic force acting on each

proton.

2. A straight copper wire carries a 6.0 A current from left to right in a region between the poles of large

electromagnet where a horizontal magnetic field directed at northeast with a magnitude of 2.10 T at 30 degrees

northeast. What is the magnetic force on a 2m section of a wire?

Calculate the percentage error for each of the resistor if the real values of the resistor is given as R1=100ohms

Two small charged metal spheres are placed 20cm apart in air. If they have +20 x 10^-6 C and +4 x 10^-6 C charges on them respectively, what force acts on them? What is the electric field intensity halfway between them?

1.  A charge of Q₁ of 2 x 10^-6 C is placed on a line between two charges Q₂ of 1 x 10^-6 C and Q₃ of -6 x 10^-6 C. Q₁ is 10 x 10^-4 m from Q₂ and 20 x 10^-4 m from Q₃. What is the net force on Q₁?

The electric field at a distance of 2 m from an infinite line charge of charge density 4 nC/m is