Physics Electromagnetic Waves Level: High School
The eye is most sensitive to light of wavelength 5.545 x 10^-7 m, which is in the green-yellow region of the visible electromagnetic spectrum . The speed of light is 3 x 10^8 m/s . What is the frequency of light ? Answer in units of Hz .Your answer must be within +-0.1% .
Physics Electromagnetic Waves Level: High School
Consider a beam of electromagnetic radiation , which is traveling along the positive z direction . Its average intensity is 316 W/m^2 . The permeability of free space is 1.257 x 10^-6 N/A^2 and the speed of light is 3 x 110^8 m/s . What is its maximum electric field ? Answer in units of N/C . What is the pressure on a surface which is perpendicular to the beam and is total reflective ? What is the maximum magnetic field ?Consider the electromagnetic wave pattern as shown in the figure at “click here†. The direction in which the wave is traveling is ?
a) from-right to left
b) from left-to-right
c) Undetermined ,since the figure shows a standing wave
Question Diagram
Physics Electromagnetic Waves Level: High School
At what distance from a 50 W electromagnetic wave point source (like a light bulb) is he amplitude of the electric field 24 V/m ? micro 0 c = 376.991 ohm .
Physics Electromagnetic Waves Level: High School
In the diagram on the right , the electric field vector points upwards and the magnetic field vector points out of the page directly at you . This electromagnetic wave is traveling .a) upwards
b) downwards
c) to the right
d) into the page
Physics Electromagnetic Waves Level: High School
The speed of light in vacuum is --------299, 792, 458 km/s
299, 792, 458 km/s
399, 462, 798 km/s
399, 462, 798 km/s
299, 792, 458 km/s
Physics Electromagnetic Waves Level: High School
Radio waves travel at the speed of light. The LORAN C navigation system (which has a transmitter near Searchlight , Nevada) operates on the relatively low radio frequency of 100 . KHz )a) What is the wavelength of the LORAN C signal ?
b) For comparison , what is the wavelength of the X-band (8.00 GHz = 8.00 x 10^9 Hz) telemetry signals which NASA uses to bring back picture of Saturn and its moons from the Cassini spacecraft ? ( The radio spectrum covers a wide range of wavelength)
Physics Electromagnetic Waves Level: High School
A possible means of space flight is to place a perfectly reflecting aluminized sheet into Earth’s orbit and use the light from the Sun to push this solar sail . Suppose a sail of area 6.00 x 10^4 m^2 and mass 6000 kg is placed in orbit facing the sun . The solar intensity of 1380 W/m^2 .a) What force is exerted on the sail ?
b) What is the sail’s acceleration ?
c) How long does it take the sail to reach the Moon , 3.84 x 10^8 m away ? Ignore all gravitational effect and assume that the acceleration calculated in part b remains constant
Physics Electromagnetic Waves Level: High School
Light is an example of an electromagnetic wave .a) Why is it called electromagnetic ?
b) If the light wave were generated at a frequency of 5.6 x 10^14 Hz , what would be its wavelength ?
c) If a polarizer is placed in front of the beam of light what would happen ? Explain why this occurs .
d) Radiation of light can be determined by the Stephen-Bolzmann equation .
i) What does this equation predict will happen if the temperature of the light source is increased ?
ii) In what units would delta Q / delta t be expressed ?
iii) What does the symbol e represent in this equation ?
Physics Electromagnetic Waves Level: High School
The energy density of electromagnetic radiation is some region of space is 10^-12 J/m^3 . Assume that the radiation has wavelength in the middle of the visible range , 550 nm . What is the photon density ?
Physics Electromagnetic Waves Level: High School
Dual Nature
Find the energy of a photon for each of the following cases .
a) a microwave of wavelength 3 cm .
b) blue light of wavelength 420 nm .
c) a radio wave of frequency 1070 kHz .
d) an x-ray of wavelength of 0.1 nm .
Physics Electromagnetic Waves Level: High School
The average intensity of sunlight reaching the earth is 1.390 W/m^2 with an electric field whose rms value is E = 720 N/C . A charge of 2.6 x 10^-8C is placed in the path of this electromagnetic wave .a) What is the magnitude of the electric force the charge experiences ?
b) If the charge is moving at a speed of 3.7 x 10^4 m/s , what is the magnitude of the magnetic force that the charge could experience ?
Physics Electromagnetic Waves Level: High School
Which one of the following is not a common use of microwave ?a) cooking
b) radar
c) medical imaging
d) communication
Physics Electromagnetic Waves Level: High School
Type of EM waves having the highest frequency in this list is .a) ultraviolet
b) infrared
c) x-rays
d) microwave
e) gamma rays
Physics Electromagnetic Waves Level: High School
The greenhouse effect occurs because .a) Low frequency EM waves are reflected from the atmosphere .
b) High frequency EM waves are reflected from the atmosphere .
c) The ozone layer absorbs ultraviolet light .
d) Carbon dioxide in the atmosphere absorbs IR emission re-radiated from the earth’s .
e) None of the above .
Physics Electromagnetic Waves Level: High School
An electromagnetic wave has an electric field with peak value 250 N/C . What is the average intensity of the wave ?a. 0.66 W/m^2
b. 0.89 W/m^2
c. 83 W/m^2
d. 120 W/m^2
e. 170 W/m^2
