Physics Unit 9 Test

De-Broglie waves are associated with

• Moving charged particles only

• Moving neutral particles only

• Accelerated charged particle

• All particles in motion

Stopping potential for photoelectrons

• Does not depend on the frequency of the incident light

• Does not depend upon the nature of the cathode material

• Depends on both the frequency of the incident light and nature of the cathode material

• Depends upon the intensity of the incident light

The slope of the stopping potential versus ‘frequency graph for photoelectric effect is equal to

• h

• he

• h/e

• e

In photoelectric effect if the intensity of light is doubled then maximum kinetic energy of photoelectrons will become

• Double

• Half

• Four-time

• No change

In a semiconductor diode, the barrier offers opposition to only

• Majority carries in both regions

• Free electron in the n-regions

• Minority carries in both regions

• Holes in the p-regions

Which of the following is the correct statement?

• No photo electronic emission takes place if the frequency of radiation however intense it may be is less than a certain critical value called threshold frequency

• Threshold frequency depends upon the nature of the metal surface

• The maximum energy of a photoelectron is a function of frequency rather than intensity of radiation

• All of the above

A photon of wavelength 900nm behaves like a particle of mass

• 5.53 × 10^-36kg

• 0 kg

• 2.46 × 10^-36kg

• 1.84 × 10^-44kg

The curves (A), (B), (C) and (D) show the variation between the applied potential difference (V) and the photoelectric current (I), at two different intensities of light (I1 > I2). In which figure is the correct variation shown

• 
• 
• 
• 

The stopping potential in an experiment on the photoelectric effect is 1.5 V. What is the maximum kinetic energy of the photoelectrons emitted?

• 1.5 eV

• 3 eV

• 4.5 eV

• 6 eV

If K.E. of free electron is doubled, its de Broglie wavelength will change by factor

• 2