Electricity and Magnetism Answers

The electric field produced by, a disk of radius R that carries uniformly distributed positive charge q, at a point P located on the axis of the disk (which we choose as the positive z- axis) a distance z from its center is given by equation;

E_z= 1/(4πε_0 ) 2qz/R^2 (1- z/√(z^2+R^2 ))
Starting with above equation write an equation in vector form that gives the electric field when point P is located either on the positive or negative axis of the disk of charge.

The electric field produced by, a thin rod of length L that lies along the z-axis and carries uniformly distributed positive charge q, at a point P located on the perpendicular bisector of the rod (the positive y-axis) a distance y from its center is given by equation.


E= 1/(4πε_0 ) q/(y√(y^2+L^2/4))

(a). Does this equation remain valid if the point P is located at negative y-axis? Explain.
(b) Write an equation similar to above equation if the point P is instead located a distance x from the rod on the positive or negative x-axis.
(c) Write an equation in vector component form for the electric field when point P is located a distance d from the rod on the 45º line that bisects the positive x and y-axes.
(d) Write an equation in vector component form that gives the electric field when point P is located at an arbitrary point x, y anywhere in the xy-plane. Check that the components have the correct signs when the point x, y is located in each of the four quadrants.

The electric field produced by, a thin rod of length L that lies along the z-axis and carries uniformly distributed positive charge q, at a point P located on the perpendicular bisector of the rod (the positive y-axis) a distance y from its center is given by equation.


E= 1/(4πε_0 ) q/(y√(y^2+L^2/4))

In a lossy dielectric material of relative permittivity 12, the displacement current density is 25 times greater than conduction current at 1Mhz. Find the conductivity of the dielectric?

For normal incidennce at the air dielectric interface with dielectri constant Er=4. Find the fraction of energy reflected into the air?

In a mass spectrometer, a particle is ionized to include an additional proton. It is then accelerated to a velocity of 54000 m/s and allowed to enter a magnetic field of 10 T where it is deflected in a semi-circular path with a radius of 2 mm. What is the mass of the particle?

A current carrying rectangular wire loop with width a = 0.12m and length b= 0.2m is in the xy plane, supported by a non-conducting , frictionless axle of negligible weight. A current of I = 3A travels counterclockwise in the circuit. Calculate the magnitude and direction of the force exerted on a) left, b) right segments of wire by a uniform magnetic field of 0.250 T that points +x-direction, c) magnetic force exerted on the top, d) magnetic force exerted on the bottom segments and e) find the magnitude of net torque on the loop about the axle.

If a weather station uses electromagnetic waves with a frequency of 2.85 x 10^9 Hz, what is the length of the wave

The current in the primary coil of the transformer below is 0.09 A. The efficiency is 85%. Find the output power of the transformer.

An electrical mini speaker for home requires 9 V to function. The voltage of the electrical supply is 240 V. What is the turns ratio of the transformer that must be used?