Electricity and Magnetism Answers

two points charge q1=+25nC and q2=-75nC are separated by a distance of 3.0cm. Find the Magnitude and direction of electric force that exerts on q2 and electric force that q2 exerts on q1

Force is equal to

Good day. I would like to know what is the relationship between the surface area of a conductor and the current through it. Is there a formula to relate these two? Thank you in advance.

 A magnetic dipole ~m = mˆk is placed in an otherwise uniform external magnetic

field B~

ex = −B0

ˆk .

(a) Write an expression for the radial, polar and azimuthal components of magnetic

field B~ (r, θ, φ) due to ~m only . (1 mark)

(b) Show that in the combined field there exists a certain spherical surface centered

on the dipole through which no field lines pass, Find its radius. (2 marks)

(c) Sketch the magnetic field lines in the region around the dipole in presence of

B~

ex.

Two electric charges q₁ and q₂ are initially separated by distance r_i . When the two charges are moved farther apart, the magnitude of the electric force reduces three times the initial. How many times the separation distance between them increases?

A small sphere of charge q₁ = +8.00 x 10^-5 C is at a distance r = 2.67 m from another small sphere of charge q₂ = -6.00 x 10^-5 C (a) What is the magnitude of the attractive electric force between these two charged spheres? (b) How many excess protons are there in the small sphere with charge q₁ ? (c) How many excess electrons are there in the small sphere with charge q₂ ?

. How much kinetic energy does the object receive when an object with 7 coulombs of charge is accelerated using an electrical potential difference of 12 volts?

A helium nucleus is sent at high speed toward a metal sphere with a charge of 1.5 nC what is the force acting on the helium nucleus when it is 3.5 mm away from the metal sphere

1.     A parallel plate capacitor consists of two rectangular plates, each with an area of  and are separated from each other by a 2.00 mm thick dielectric with a dielectric constant of 5.26. The capacitor is connected to a 12.0 V battery. How much energy is stored in the capacitor?

a car starts at rest covering a distance of 200m. It continues moving with a constant velocity for another 300m before coming to rest in the last 100m . Determine the velocity of the car when it was moving with a constant velocity