Exam 25: Electromagnetic Induction and Electromagnetic Waves

-In the figure,a C-shaped conductor is in a uniform magnetic field B,which is increasing.The polarity of the induced emf in terminals X and Y is:

A closed-loop conductor with radius 2.0 m is located in a changing magnetic field.If the maximum emf induced in the loop is 2.0 V,what is the maximum rate at which the magnetic field strength is changing if the magnetic field is oriented perpendicular to the plane in which the loop lies?

-In the figure,the orientation of the transmission axis for each of three polarizing sheets is labeled relative to the vertical direction.A beam of light,polarized in the vertical direction,is incident on the first polarized with an intensity of 1000 W/m².What is the intensity of the beam after it has passed through the three polarizing sheets when θ₁ = 30º,θ₂ = 30º,and θ₃ = 60º?

What is the energy of a photon in light of 610 nm wavelength? Express your answer in eV.

An 800 kHz radio signal is detected at a point 9.5 km distant from a transmitter tower.The electric field amplitude of the signal at that point is 230 mV/m.Assume that the signal power is radiated uniformly in all directions and that radio waves incident upon the ground are completely absorbed.The average electromagnetic energy density at that point is closest to:

Light of intensity So and polarized horizontally passes through three polarizers.The first and third are horizontal,but the second is oriented 0.34907 rad to the horizontal.In terms of So,what is the intensity of the light that passes through the set of polarizers?

By how much are the electric and magnetic fields out of phase in an electromagnetic wave?

-In the figure,a straight wire carries a current I.The wire passes through the center of a toroidal coil.The current is quickly reduced to zero.The induced current through the resistor R is:

An electromagnetic wave has a magnetic field with Brms of 9.0 uT.What is Erms for this wave?

According to Lenz's law,the induced current in a circuit must flow in such a direction to oppose the flux through that circuit.

Unpolarized light is incident upon two polarization filters that do not have their transmission axes aligned.If 14% of the light passes through,what is the measure of the angle between the transmission axes of the filters?

A uniform electric field perpendicular to a spherical surface of radius 5.00 cm is increasing at a rate of 4.0 V/m · µs.Find the displacement current through the spherical surface.

You are pulling a rectangular coil through a uniform static magnetic field that extends well beyond the boundary of the coil.The faster you pull this coil perpendicular to the field,the greater the emf that is induced in it.

A bar magnet is oriented vertically,and a flat coil with its plane oriented horizontally is located a short distance just below the bottom of this magnet.The instant after the magnet is dropped from rest,you observe that a counterclockwise current is induced in the coil,as viewed from below the coil.From this observation,you can conclude that the lower end of the magnet is a south pole.

A 7.55 × 10¹⁴ Hz electromagnetic wave propagates in carbon tetrachloride with a speed of 2.05 × 10⁸ m/s.The wavelength of the wave in carbon tetrachloride is closest to:

A circular metal loop surrounds an ideal solenoid such that the plane of the loop is perpendicular to the cylindrical axis of the solenoid.If the current in the solenoid is steadily increased,no emf is induced in the loop because the magnetic field outside an ideal solenoid is zero.

A loop of wire is situated inside a large solenoid,with the plane of the loop initially perpendicular to the axis of the solenoid.Current can be made to flow through the loop of wire if

The speed of all electromagnetic waves through vacuum is equal to the reciprocal of the square root of μ_oε_o.

A circular coil of 20 turns and radius 5 cms is placed with its plane oriented at 90° to a magnetic field of 0.1 T.The field is now increased at a steady rate,reaching a value of 0.5 T after 4 seconds.What emf is induced in the coil?

A conducting bar is free to slide horizontally on the rails of a conducting frame,as shown in the figure.A lightbulb is attached to the right end of the rails.A spatially uniform magnetic field is oriented vertically (perpendicular to the horizontal plane of the rails and bar).Initially the bar is stationary.The strength of the magnetic field begins increasing in time at a constant rate,which induces a current through the bar,frame,and lightbulb.The bar begins to move due to the magnetic force exerted on it.Once the bar begins to move,the brightness of the lightbulb