In an experiment different wavelengths of light, all able to eject photoelectrons, shine on a freshly prepared (oxide-free) zinc surface. Which statement is true?
a. The number of photoelectrons emitted per second is independent of the intensity of the light for all the different wavelengths.
b. The number of photoelectrons emitted per second is directly proportional to the frequency for all the different wavelengths.
c. The maximum kinetic energy of the photoelectrons emitted is directly proportional to the frequency for each wavelength present.
d. The maximum kinetic energy of the photoelectrons has a linear relationship with the frequency for each wavelength present.
e. The maximum kinetic energy of the photoelectrons is proportional to the intensity of the light and independent of the frequency.
[Ques. 2] The Moon's albedo is ______________.
Fill in the blank(s) with correct word
[Ques. 3] A sound level of 93 dB is how many times as intense as one of 73 dB?
[Ques. 4] Microscopes are inherently limited by the wavelength of the light used. How much smaller (in order of magnitude) can we see using an electron microscope whose electrons have been accelerated through a potential difference of 50000 V than using red light (500 nm)?
a. 3
b. 4
c. 5
d. 6
e. 14
[Ques. 5] Earth's albedo is ______________.
Fill in the blank(s) with correct word
[Ques. 6] A particular sound with large intensity is reduced 1000-fold. What is the decibel reduction?
[Ques. 7] An electron is accelerated through a potential difference of 25000 V. What is the de Broglie wavelength of the electron (in m)?
a. 5.9 1012
b. 6.8 1012
c. 6.5 1012
d. 7.8 1012
e. 5.5 1012
[Ques. 8] The fraction of incident sunlight reflected by a celestial body is called its ______________.
Fill in the blank(s) with correct word
[Ques. 9] The intensity of a 70-dB whistle is doubled. What is the new decibel level?
[Ques. 10] A neutron has a mass of 1.67 1027 kg. Its de Broglie wavelength is 1.4 1010 m. What temperature would it correspond to if we had a monatomic gas having the same average kinetic energy (in C)?
a. 273
b. 25
c. 36
d. 309
e. 51
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