A circular region 19.0 m in radius is filled with an electric field perpendicular to the face of the circle. The magnitude of the field in the circle varies with radius and time as E(r,t) = Arcos(at) where A 1000. V/m2 and -5.00 x 10's. What is the maximum value of the magnetic field at the edge of the region? T

An electron moving with a velocity v=(4.0i+3.0j+2.0k)106m/s enters a region where there is a uniform electric field and a uniform magnetic field. The magnetic field is given by v=(1.0i2.0j+4.0k)102T. If the electron travels through a region without being deflected, what is the electric field?

The magnetic field between the poles of a horseshoe electromagnet is uniform and has a cylindrical symmetry about an axis from the middle of the South Pole to the middle of the North Pole. The magnitude of the magnetic field changes as a rate of dB/dt due to the changing current through the electromagnet, Determine the electric field at a distance r from the center.

On its highest power setting, a microwave oven increases the temperature of 0.400 kg of spaghetti by 45.0°C in 120 s. (a) What was the rate of energy absorption by the spaghetti, given that its specific heat is 3.76103J/kg.C ? Assume the spaghetti is perfectly absorbing. (b) Find the average intensity of the microwaves, given that they are absorbed over a circular area 20.0 cm in diameter. (C) What is the peak electric field strength of the microwave? (d) What is its peak magnetic field strength?

If electric and magnetic field strengths vary sinusoidally in time at frequency 1.00 GHz, being zero at t=0, then E=E0sin2ft. (a) When are the field strengths next equal to zero? (b) 4Jhen do they reach their most negative value? (c) How much time is needed for them to complete one cycle?

An incandescent light bulb emits only 2.6 W of its power as visible light. What is the rms electric field of the emitted light at a distance of 3.0 m from the bulb?

A nonconducting hard rubber circular disk of radius R is painted with a uniform surface charge density tr. It is rotated about its axis with angular speed . (a) Find the magnetic field produced at a point on the axis a distance h meters from the center of the disk, (b) Find the numerical value of magnitude of the magnetic field when =1C/m2 , R = 20 cm, h = 2 cm, and magnetic field of Earth, which is about 1/2 Gauss. =400rad/sec , and compare it with the magnitude of

At a particular instant an electron is traveling west to east with a kinetic energy of 10 keV. Earth's magnetic field has a horizontal component of 1.8105 T north and a vertical component of 5.0105 T down. (a) What is the path of the election? (b) What is the radius of curvature of the path?

Unreasonable results Frustrated by the small Hall voltage obtained in blood flow measurements, a medical physicist decides to increase the applied magnetic field strength to get a 0.500-V output for blood moving at 30.0 cm/s in a 1.50-cm-diameter vessel. (a) What magnetic field strength is needed? (b) What is unreasonable about this result? (C) Which premise is responsible?

A parallel-plate capacitor with plate separation d is connected to a source of emf that places a time-dependent voltage V(t) across its circular plates of radius r0and area (a) Write an expression for the time rate of change of energy inside the capacitor in terms of V(t) and dV(t)/ dt. (b) Assuming that V(t) is increasing with time, identify the directions of the elecuic field lines inside the capacitor and of the magnetic field lines at the edge of the region between the plates, and then the direction of the Poynting vector S at this location. (c) Obtain expressions for the time dependence of E(t), for B(t) from the displacement current, and for the magnitude of the Poynting vector at the edge of the region between the plates. (d) From S , obtain an expression In terms of ‘(t) and dV(t)/dt for the rate at which electromagnetic field energy the region between the plates. (e) Compare the results of pails (a) and (d) and explain the relationship between them.