Electricity and Magnetism Answers

Discuss Poynting vector related to power flow in free space. A uniform plane wave at frequency of 200 MHz travel in vacuum along positive Y direction. The electric field at some instance is given as  . Find the phase constant of the wave.

 A wire of length 0.050𝑚 and carries a current 𝐼 is in a horizontal uniform magnetic field B of 2.50 𝑇 which is perpendicular to the rod. The weight of the wire is 0.80𝑁. What is the value of the current 𝐼 if the magnetic force on the wire equals its weight?

 A flat circular coil which has 𝑁 turns each of diameter d carries a current 𝐼. If 𝜇0 is the permeability of free space, what is the expression of magnetic field 𝐵 at the center of the coil? 

why must the test charge qo in the definition of the electric field be vanishingly small?

1. A particle of charge +7.5 μC and a speed of 32.5 m/s enters a uniform magnetic field whose magnitude is 0.50 T. Find the magnitude and direction of the magnetic force on the particle.

2. A uniform magnetic field of magnitude 2 G is directed in the +x direction on the x-y plane. A proton enters the magnetic field in the +y direction with a speed of 2 x 10⁶ m/s. What is the magnitude and direction of the magnetic force of the proton? (1T = 10,000 G)

3. A circular coil 50 cm in diameter is rotating in a magnetic field directed upward with a magnitude of 65 milliTesla. Calculate the magnetic flux through the coil at a) horizontal position and b) tilted 60^o from the horizontal position.

Consider the two dipoles that are located on a line with dipole moments - 5 × 10−9 𝐶. 𝑚 and 9 × 10−9 𝐶. 𝑚, Find the Electric potential at the center of the line. Now, replace the electric dipoles with the magnetic dipoles such that their dipole moments are 5 × 10−9 𝐴. 𝑚2 and 9 × 10−9 𝐴. 𝑚2 . Find the magnetic field at the center. 

A parallel plate capacitor is connected to a DC power supply with potential difference V = 20 V. A dielectric slab of thickness d = 10 cm is then inserted between the plates of the capacitor, completely filling the space between them. The dielectric constant of the slab is κ = 2. Calculate the induced surface charge density, σi, on the surface of the slab (permittivity of vacuum is ϵ0= 8.85×10-12F/m).

A copper wire has a resistance of 15.0 ohms at a temperature of 14 C. After a current passes through the windings, the resistance rose to 12.5 ohms. To what temperature was the wire heated?

Calculate the induced EMF if the conductor length in the magnetic

field is 100mm, the velocity of the wire is 12m/s, the magnetic flux

density is 0.75 T and the angle the conductor makes with the

magnetic field is 38 0 .

a proton moving at right angle in a magnetic field of 0.1 T, experience a force of 2*10^-12N, thus the speed of proton is