Electricity and Magnetism Answers

Which of the following statements are not true about electric force Fe and magnetic force Fm on a charged particle? (a) E and Fe are parallel to each other, whereas B and Fm are perpendicular to each other. (b) Both Fe and Fm depend on the velocity of the charged particle. (c) Both Fe and Fm can perform work. (d) Both Fe and Fm are produced when a charged particle moves at a constant velocity. (e) Fm is generally small in magnitude in comparison to Fe. (f) Fe is an accelerating force, whereas Fm is a purely deflecting force

What is (a) the position, and (b) the size, of the image of a 7.60cm-high object placed 1.00 m from a +50.0-mm-focal-length camera lens?

A 1.50-cm-high object (upright arrow) is placed 20.0 cm from a concave mirror with radius of curvature 30.0 cm. Determine (a) the position & (b) the size of the image. Construct a ray-diagram for the image formation of this object on the concave mirror by using appropriate scale.

Find the critical angle for an air–water boundary. (The index of refraction of water is 1.33.)

Light travelling in air strikes a flat piece of uniformly thick glass at an incident angle of 60.0°, as shown. If the index of refraction of the glass is 1.50, (a) what is the angle of refraction θA in the glass; (b) what is the angle θB at which the ray emerges from the glass?

Two flat mirrors are perpendicular to each other. An incoming beam of light makes an angle of 15° with the first mirror as shown below. What angle will the outgoing beam make with the surface of the second mirror?

(a) What is the wavelength (in meters) of a 93.3 MHz Radio wave frequency? (b) What is the frequency (in Hz) of an x-ray beam with wavelength of 0.0100 nm?

Two positive charges are separated by a distance R. If the distance between the charges is reduced to R/2, what happens to the total electric potential energy of the system

The electric potential in some region in space is given by V (r) = C/r where r = p x 2 + y 2 + z 2 and C is a positive constant. (a) calculate an expression for the electric field in this region. (b) note that ~r = xˆi + ˆj + z ˆk and ~r = rrˆ, express E~ in spherical coordinates. Here ˆr is the radial unit vector of spherical coordinates, sometimes denoted as ˆer. (c) Look and report the expression for the gradient operator in spherical coordinates. Re-derive the expression for E~ , now directly in spherical coordinates

A charge Q is uniformly distributed throughout a sphere of radius a. Taking the potential 

at infinity as zero, the potential at r =b < a is