Electricity and Magnetism Answers

AM 630 is where I listen to sports. The frequency is 630 kHz( or 630,000 hz). What is the wavelength

1.0 Three equal charges of +6 nC are located at the corners of an equilateral triangle (3) whose sides are 12 cm long, as shown below. Find the potential at the center of the triangle.

2.0 Define the electronvolt.

(2)

oint A. -9 +4x10 C

 2.1 In the Millikan experiment, an oil drop carries four electronic charges (3)

and has a mass of 1.8 x 10-12 g. It is held almost at rest between two horizontal charged plates 1.8 cm apart. What voltage must there be between the two charged plates? (Take electron charge e = 1.60 x 10-19 C)

3.0 Compute the energy stored in a 60𝑝𝐹 capacitor (5)

a) When Charged to a potential difference of 2𝑘𝑣

b) When the charge on each plate is 30𝑛𝐶

A potential difference of 100 V is applied to the primary coil of a transformer. The current through the primary coil is 2.0 A. The potential difference across the secondary coil is 15 V

Calculate the current flowing through the secondary coil.

3. The electric (E) and magnetic (H) field vectors in a medium are given by

𝑬 = 𝒊^ 20𝑐𝑜𝑠(𝜔𝑡 + 𝜋𝑦)𝑉/𝑚 , 𝑯 = 𝒌^ 20 𝑐𝑜𝑠(𝜔𝑡 + 𝜋𝑦)𝐴/𝑚

𝜂

Use Maxwell’s equations to determine η and ω. Assuming that for the medium 𝜀 = 36𝜀𝑜 ,

𝜇 = 𝜇𝑜 .

Two parallel straight wires 10.0 cm apart carry currents in opposite directions (Fig. 20–24). Current I_1=5.0 A is out of the page, and I_2=7.0 A is into the page. Determine the magnitude and direction of the magnetic field halfway between the two wires.

What is the maximum force on an aluminium particle with a +0.1 𝜇𝐶 of charge, which is passing between the poles of a 1.5 𝑇 permanent magnet at a speed of 5 𝑚𝑠−1? In what direction is the force?

Hint: Assume the direction of the magnetic field as preferred. Draw a diagram showing all the relevant vectors in terms of their components. Use the equation for the force on a moving charged particle in a magnetic field.

Consider the configuration shown below, with a negative charge Q0 at position x0=0 and another positive charge Q1 at position 1 along the x-axis. Determine the position At which position x2 could another positive charge charge Q2 be added, such that the total force on Q0 is 0? Give two examples of x2 and corresponding Q2, in terms of x0, x1, Q0 and Q1 (or a subset of these variables). 

If an charged object transfers its charges to another uncharged object will it mass be affected? And how does it transfers its charges?

What happens when a long, straight conductor is moved through a uniform magnetic field at constant velocity? Assume that the conductor moves perpendicular to the field.