Question 1

Alpha particles (m = 6.6 * 10-27 kg,q = +2e)are accelerated through a potential difference of 11,100V,what is their de Broglie wavelength?

Accepted Answer

A) 1.9 * 10-49 m 
B) 1.5 * 10-15 m 
C) 9.7 * 10-14 m 
D) 4.5 * 10-12 m 
E) 9.0 * 10-12 m 
A) 1.9 * 10-49 m 
B) 1.5 * 10-15 m 
C) 9.7 * 10-14 m 
D) 4.5 * 10-12 m 
E) 9.0 * 10-12 m

Question 2

Protons and neutrons are fermions.The nucleus of helium-4 contains two protons and two neutrons.Which of the following spin states are allowed for the nucleus of a helium-4 atom?

Accepted Answer

A) both protons spin up,both neutrons spin up 
B) both protons spin up,both neutrons spin down 
C) one proton and one neutron spin up and one proton and one neutron spin down 
D) All are correct. 
E) None are correct. 
A) both protons spin up,both neutrons spin up 
B) both protons spin up,both neutrons spin down 
C) one proton and one neutron spin up and one proton and one neutron spin down 
D) All are correct. 
E) None are correct.

Question 3

During Compton scattering,when a beam of monochromatic x-ray photons scatter off stationary electrons,their wavelength increases.What is the maximum possible increase?

Accepted Answer

A) 2.43 pm 
B) 4.85 pm 
C) There is no maximum value. 
D) The wavelength of the x-ray photons doesn't increase.It decreases. 
A) 2.43 pm 
B) 4.85 pm 
C) There is no maximum value. 
D) The wavelength of the x-ray photons doesn't increase.It decreases.

Question 4

The work function of a certain material is 4.9 eV.What is the photoelectric minimum (threshold)frequency for this material?

Accepted Answer

A) 1.18 * 1015 Hz 
B) 2.23 * 1015 Hz 
C) 9.01 * 1014 Hz 
D) 3.48 * 1015 Hz 
E) 2.56 * 1015 Hz 
A) 1.18 * 1015 Hz 
B) 2.23 * 1015 Hz 
C) 9.01 * 1014 Hz 
D) 3.48 * 1015 Hz 
E) 2.56 * 1015 Hz

Question 5

X-rays with a wavelength of 7.02 * 10-12 m strike a stationary electron and the reflected photon is scattered 75 degrees relative to the incident photon.What is the wavelength of the scattered photon?

Accepted Answer

A) 1.80 * 10-12 m 
B) 4.59 * 10-12 m 
C) 8.82 * 10-12 m 
D) It could have any wavelength of 7.02 * 10-12 or longer. 
E) It could have any wavelength of 7.02 * 10-12 or shorter. 
A) 1.80 * 10-12 m 
B) 4.59 * 10-12 m 
C) 8.82 * 10-12 m 
D) It could have any wavelength of 7.02 * 10-12 or longer. 
E) It could have any wavelength of 7.02 * 10-12 or shorter.

Question 6

The work function of a certain material is 4.9 eV.What is the photoelectric cut-off wavelength for this material?

Accepted Answer

A) 1.3 * 10-7 m 
B) 2.5 * 10-7 m 
C) 3.3 * 10-7 m 
D) 3.9 * 10-7 m 
E) 4.4 * 10-7 m 
A) 1.3 * 10-7 m 
B) 2.5 * 10-7 m 
C) 3.3 * 10-7 m 
D) 3.9 * 10-7 m 
E) 4.4 * 10-7 m

Question 7

A 20.0-kg particle has a deBroglie wavelength of 10.0 cm.How fast is the particle moving?

Accepted Answer

A) 1.30 * 10-34 m/s 
B) 2.64 * 10-34 m/s 
C) 3.31 * 10-34 m/s 
D) 3.98 * 10-34 m/s 
E) 4.40 * 10-34 m/s 
A) 1.30 * 10-34 m/s 
B) 2.64 * 10-34 m/s 
C) 3.31 * 10-34 m/s 
D) 3.98 * 10-34 m/s 
E) 4.40 * 10-34 m/s

Question 8

If light of wavelength 320 nm causes a 2.1 eV photon to be emitted from a metal surface,which of the following statements holds?

Accepted Answer

A) The work function must be greater than 2.1 eV. 
B) The work function must be less than 1.8 eV. 
C) The work function must be 3.9 eV. 
D) The cut-off wavelength for photo emission is less than 320 nm. 
E) The energy of a 320 nm photon must be 2.1 eV. 
A) The work function must be greater than 2.1 eV. 
B) The work function must be less than 1.8 eV. 
C) The work function must be 3.9 eV. 
D) The cut-off wavelength for photo emission is less than 320 nm. 
E) The energy of a 320 nm photon must be 2.1 eV.

Exam 36: Quantum Physics

Alpha particles (m = 6.6 * 10-27 kg,q = +2e)are accelerated through a potential difference of 11,100V,what is their de Broglie wavelength?

Protons and neutrons are fermions.The nucleus of helium-4 contains two protons and two neutrons.Which of the following spin states are allowed for the nucleus of a helium-4 atom?

During Compton scattering,when a beam of monochromatic x-ray photons scatter off stationary electrons,their wavelength increases.What is the maximum possible increase?

The work function of a certain material is 4.9 eV.What is the photoelectric minimum (threshold)frequency for this material?

X-rays with a wavelength of 7.02 * 10-12 m strike a stationary electron and the reflected photon is scattered 75 degrees relative to the incident photon.What is the wavelength of the scattered photon?

The work function of a certain material is 4.9 eV.What is the photoelectric cut-off wavelength for this material?

A 20.0-kg particle has a deBroglie wavelength of 10.0 cm.How fast is the particle moving?

If light of wavelength 320 nm causes a 2.1 eV photon to be emitted from a metal surface,which of the following statements holds?

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X-rays with a wavelength of 7.02 * 10^-12 m strike a stationary electron and the reflected photon is scattered 75 degrees relative to the incident photon.What is the wavelength of the scattered photon?