Electricity and Magnetism Answers

negative charge of -200 uC and a positive charge of 800 uC are separated by a distance of 0.30 cm.

Riley, the dog, walks around with 1.23 x 10^5 electrons. How much charge is she carrying around?

Explain with the aid of a ray diagram, how a converging (convex) lens is used in a simple camera

when resistors are connected in series and parallel, what happens to the current and voltage in the circuit

a small object is placed 30cm from a diverging (concave) lens of focal length 10cm. determine by scale drawing or by calculation (stating any sign convention used) the position and nature of the image

-3q and 2q charges are placed at some distance. Where you would place third charges q so that the new force on this charge is zero.

Two identical metallic spheres are suspended as bobs of a simple pendulum as shown in the figure. The spheres come to equilibrium when given a charge of +7.5 x 10^-9 C, with each string making an angle 5⁰ with the vertical. The string is 0.5 m long. Find the electric force between the spheres.

State Maxwell’s equations in terms of electric (E) and magnetic (B) fields in a region in which 

there are charge and current densities (p and J respectively) which are functions both of space and 

time. 

The maximum electric field in a plane electromagnetic wave is 600N/C. The wave is going in the 

x-direction and the electric field is in the y-direction. Find the maximum magnetic field in the wave 

and its direction.

An inductor (L = 20 mH), a resistor (R = 100 Ω) and a battery (ε = 10 V) are connected in series. 

Find

i. The time constant

ii. The maximum current

iii. The time elapsed before the current reaches 99% of the maximum value.