Electricity and Magnetism Answers

magnitude of specific heat discontinuity in curie weiss theory
1)3NK/2
2)NK/2
3)4NK/3

THe plates of a thompson q/m apparatus are 5 cm long and separated by 1 cm. The end of the plates are 25 cm from tube screen. The kinetic energy of the electrons is 2000 eV.
a) If a potential of 20 V is applied across the deflection plates, by how much will the beam deflect

A charge +q is placed at the centre of the base of a cone . What is the flux through its curved surface ?

A group of students are recreating Millikan’s Oil Drop experiment in which a charged oil droplet is suspended in the electric field created by two horizontal charged plates. The droplet experiences a downward force due to gravity and an upward force due to the electrostatic force from the charges. The forces are balanced so that the droplet does not accelerate. In this case, the two horizontal parallel plates are 0.80 cm apart. A sphere of mass 2.73 x 10–13 kg remains stationary when the potential difference between the plates is 315 V with the upper plate negative.

Draw the FBD of the oil droplet.

Is the sphere positively or negatively charged? Explain how you know.

Calculate the magnitude of charge on the sphere.

How much excess or deficit of electrons does the sphere have?

What electric potential would be measured at a distance of 12cm from a charge of 3.5 x 10-5 C? What would be the potential if the distance were increased to 30 cm?

How much work must be done to carry a 3.0 x 10-5 C charge from 12 cm to 30 cm?

Three point charges A, B, and C sit on the corners of an equilateral triangle with side length 10cm. Each charge has a of magnitude 2.32 x 10-6 C with charge A and C being negative and B being positive, as shown in the diagram below. What is the net force on each of the point charges? Include vector diagrams for each charge in your answer.

The ratio of skin depth in copper at 1 kHz to that at 100 MHz is approximately :
(A) 3
(B) 30
(C) 300
(D) 3000

The vector potential at the position defined by vector r in a uniform magnetic field B can be represented

Sodium has a work function of 2.36eV. If a beam of monochromatic 442-mm light is incident upon a sample sodium, will electrons be ejected? At what speed?

Explain what you understand by the apparent magnitude of a star. How is it related
to the brightness of the star? An object A has an apparent magnitude of –5. Another
object B has an apparent magnitude of –10. Calculate the ratio of their brightness