Question 1

A possible means of spaceflight is to place a perfectly reflecting aluminized sheet into Earth orbit and use the light from the Sun to push this solar sail. If a huge sail of area 6.00 × 105 m² and mass 6000 kg were placed into orbit and turned toward the Sun, what would be the force exerted on the sail? (Assume a solar intensity of 1380 W/m².)

Accepted Answer

The answer of A possible means of spaceflight is to...

Question 2

A spherical particle of density and 2.00-mm radius is located at the same distance from the Sun as the Earth (RSE = 1.5 × 1011 m, G = 6.67 × 10-11 Nm²/kg2, S = 1365 W/m², M S = 1.99 × 1030 kg) . If the particle absorbs 100 percent of the sunlight reaching it, the ratio of the force exerted by the solar radiation to the force of gravity exerted on the particle by the Sun is

Accepted Answer

The answer of A spherical particle of density  and...

Question 3

The correct form of Ampere's law for circuits with gaps in them is

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The answer of The correct form of Ampere's law for...

Question 4

The speed of light is given by the value of

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The answer of The speed of light is given by...

Question 5

Since ε0 = 8.85 × 10−12 C2 / N ⋅ m², the units of ε0E2 can be reduced to

Accepted Answer

The answer of Since ε0 = 8.85 × 10−12 C2...

Question 6

In the atmosphere, the shortest wavelength electromagnetic waves are called

Accepted Answer

Gamma rays have the shortest wavelength among the options listed, making them the highest energy electromagnetic waves in the atmosphere.

Question 7

You can raise the temperature of an object with

Accepted Answer

All of the options listed, microwaves, infrared waves, and ultraviolet rays, can increase the temperature of an object. Microwaves and infrared waves are commonly used for heating, while ultraviolet rays, despite being less commonly associated with heating, can also raise temperatures.

Question 8

An open circuit consists of a 12-μF parallel plate capacitor charged to 200 V and a 10-Ω resistor. At the instant when a switch closes the circuit (with no battery in it) the displacement current between the plates of the capacitor is

Accepted Answer

The answer of An open circuit consists of a 12-μF...

Question 9

The magnetic field amplitude in an electromagnetic wave in vacuum is related to the electric field amplitude by B =

Accepted Answer

The answer of The magnetic field amplitude in an electromagnetic...

Question 10

High frequency alternating current is passed through a solenoid that contains a solid copper core insulated from the coils of the solenoid. Which statement is correct?

Accepted Answer

At high frequencies, circular currents (also known as eddy currents) are induced in the solid copper core due to the changing magnetic field produced by the solenoid. These circular currents encounter resistance as they flow through the copper, causing the copper core to heat up. Therefore, option D is the correct choice. Options A and B are incorrect because they do not provide a valid explanation for why the copper core remains cool or heats up. Option C is incorrect because it suggests that the induced emf parallel to the solenoid axis causes the heating, which is not entirely true. Option E is also incorrect because although the electric field induced in the copper is parallel to the magnetic field produced by the solenoid, this is not the main reason why the copper core heats up.

Question 11

Two identical silver spheres of mass m and radius r are placed a distance R (sphere 1) and 2R (sphere 2) from the Sun, respectively. The ratio of the pressure of solar radiation on sphere 2 to that on sphere 1 is

Accepted Answer

The answer of Two identical silver spheres of mass m...

Question 12

​Unpolarized light is passed through three successive Polaroid filters, each with its transmission axis at 45.0° to the preceding filter. What percentage of light gets through?

Accepted Answer

Each Polaroid filter transmits half of the light that passes through it, so the total percentage of light that gets through is:
(1/2) × (1/2) × (1/2) × 100% = 12.5%

Question 13

Near the surface of the planet, the Earth's magnetic field is about 0.50 × 10−4 T. How much energy is stored in 1.0 m³ of the atmosphere because of this field?

Accepted Answer

The answer of Near the surface of the planet, the...

Question 14

When E and B are the amplitudes of the electric and magnetic fields in an electromagnetic wave in vacuum, the total average energy density in the wave is

Accepted Answer

The answer of When E and B are the amplitudes...

Question 15

Magnetic fields are produced by

Accepted Answer

Magnetic fields can be produced by both constant electric currents and time-varying electric fields, as well as by electric currents that vary sinusoidally with time. Therefore, the correct answer is (d) all of the above.

Question 16

In an electromagnetic wave, 1) how are the electric and magnetic field directions related and 2) how is the direction of travel determined from their directions? (  is the velocity of the light wave.)

Accepted Answer

The answer of In an electromagnetic wave, 1) how are...

Question 17

The Sun radiates energy at a rate of 3.86 × 1026 W. Its radius is 7.0 × 108 m. If the distance from the Earth to the Sun is 1.5 × 1011 m, what is the intensity of solar radiation at the top of the Earth's atmosphere?

Accepted Answer

The answer of The Sun radiates energy at a rate...

Question 18

The intensity of radiation reaching the Earth from the Sun is 1350 W/m². The Earth's radius is 6.4 × 106 m. How big a force does this radiation exert on the Earth? (Assume it is all absorbed.)

Accepted Answer

The force exerted by radiation is given by the equation F = P/c, where P is the power of the radiation and c is the speed of light. In this case, the power of the radiation is 1350 W/m2 and the radius of the Earth is 6.4 × 106 m. So, the force exerted by the radiation is:F = P/c = (1350 W/m2) * (6.4 × 106 m) / (3 × 108 m/s) = 5.8 × 108 N

Question 19

At every instant the ratio of the magnitude of the electric to the magnetic field in an electromagnetic wave in vacuum is equal to

Accepted Answer

The ratio of the magnitude of the electric field to the magnetic field in an electromagnetic wave in vacuum is equal to the speed of light, which is the same for all electromagnetic waves, including radio waves and gamma rays.

Question 20

Two identical silver spheres of mass m and radius r are placed a distance R (sphere 1) and 2R (sphere 2) from the Sun, respectively. The ratio of the gravitational force exerted by the Sun on sphere 1 to the pressure of solar radiation on sphere 1 is T1; the ratio for sphere 2 is T2. The ratio of T2 to T1 is

Accepted Answer