Modern and Nuclear Physics

Who explained the photoelectric effect using the idea of photons?

1. Ernest Rutherford
2. Niels Bohr
3. Albert Einstein
4. Max Planck

The energy of a photon is given by:

1. E = h/f
2. E = ½mv²
3. E = hf
4. E = mc

In the photoelectric effect, increasing the intensity of the light (above the threshold frequency) increases:

1. The maximum kinetic energy of the electrons
2. The number of electrons emitted per second
3. The work function
4. The threshold frequency

If light is below the threshold frequency of a metal:

1. The metal heats up and emits electrons
2. Electrons are emitted slowly
3. Electrons are emitted after a delay
4. No electrons are emitted, however intense the light

The work function of a metal is:

1. The energy of the nucleus
2. The frequency of the light used
3. The minimum energy needed to remove an electron from its surface
4. The energy of an emitted electron

What is the energy of a photon of frequency 5 × 10¹⁴ Hz? (h = 6.6 × 10⁻³⁴ J s)

1. 1.3 × 10⁻⁴⁸ J
2. 7.6 × 10⁴⁷ J
3. 3.3 × 10⁻²⁰ J
4. 3.3 × 10⁻¹⁹ J

The de Broglie wavelength of a particle is given by:

1. λ = p/h
2. λ = h/p
3. λ = hp
4. λ = c/f only