Photoelectric Effect and Kinetic Energy

The video tutorial explains the photoelectric effect by solving a problem using key equations. It covers calculating the threshold frequency, finding the maximum kinetic energy, determining the maximum velocity of an electron, and calculating the stopping voltage. The tutorial emphasizes using electron volts for calculations and provides step-by-step guidance for each part of the problem.

What is the equation used to relate the energy of a photon to the maximum kinetic energy of an ejected electron?

• hf = KE_max + W

• E = mc^2

• F = ma

• V = IR

When calculating the threshold frequency, why is KE_max set to zero?

• Because the electron is at rest

• Because the work function provides just enough energy to release the electron

• Because the frequency is too high

• Because the photon energy is zero

What is the value of Planck's constant used in the threshold frequency calculation?

• 1.60 x 10^-19 C

• 9.11 x 10^-31 kg

• 4.14 x 10^-15 eV·s

• 6.63 x 10^-34 J·s

How do you calculate the maximum kinetic energy (KE_max) for a new frequency?

• By adding the work function to hf

• By subtracting the work function from hf

• By multiplying hf by the work function

• By dividing hf by the work function

What is the mass of an electron used in the velocity calculation?

• 1.67 x 10^-27 kg

• 9.11 x 10^-31 kg

• 6.02 x 10^23 kg

• 1.60 x 10^-19 kg

What is the formula used to calculate the maximum velocity of an electron?

• v = qV/m

• v = hf/m

• v = sqrt(2KE/m)

• v = u + at

What is the stopping voltage in the context of the photoelectric effect?

• The voltage at which current is maximum

• The voltage at which current is zero

• The voltage at which KE_max is zero

• The voltage at which frequency is maximum

Which equation is used to find the stopping voltage?

• E = mc^2

• F = ma

• KE_max = qV

• V = IR

What is the charge of an electron used in the stopping voltage calculation?

• 4.14 x 10^-15 C

• 9.11 x 10^-31 C

• 6.63 x 10^-34 C

• 1.60 x 10^-19 C

What is the stopping potential when the current reaches zero?

• 5.86 x 10^19 V

• 5.86 x 10^-19 V

• 5.86 x 10^-15 V

• 5.86 x 10^15 V