QCAA Physics Quantum Theory

While slit width affects the diffraction envelope and contrast, the interference pattern itself is caused by wave superposition, which can occur even if the slits are not perfectly equal in width.

Discrete packets (photons) refer to the particle nature of light; if light behaved strictly as classical particles, it would form two distinct bands rather than an interference pattern.

The distance to the screen affects the spacing of the fringes (scale), but it is not the fundamental cause of the interference phenomenon itself.

Incorrect. This result is off by a factor of 10, which would occur if the velocity was $1 \text{ m s}^{-1}$ instead of $10 \text{ m s}^{-1}$.

Incorrect. This answer is off by a factor of 100, likely due to a miscalculation of the momentum denominator $mv = 6630 \text{ kg m s}^{-1}$.

Incorrect. This is approximately the value of Planck's constant ($6.63 \times 10^{-34} \text{ J s}$), which means the momentum $mv$ was incorrectly treated as $1 \text{ kg m s}^{-1}$.

This incorrect value results from simply multiplying the energy by the speed of light ($E \times c$), ignoring Planck's constant and the correct formula.

This answer is obtained by dividing Planck's constant by the energy ($h/E$) but neglecting to multiply by the speed of light ($c$).

This value represents the wavenumber ($1/\lambda \approx 120$ m$^{-1}$), which is the reciprocal of the wavelength rather than the wavelength itself.

Using a positively ionised metal would increase the electrostatic attraction on the electrons, effectively increasing the energy required to escape and decreasing the kinetic energy.

According to the photoelectric equation $K_{max} = h\nu - \Phi$, increasing the work function ($\Phi$) reduces the remaining energy available for kinetic energy.

Increasing intensity increases the number of photons and ejected electrons (photocurrent), but does not change the energy of individual photons or the maximum kinetic energy of the electrons.

Unlike mechanical waves (like sound), photons are electromagnetic radiation and can travel through a vacuum without requiring a physical medium.

Photons mediate the electromagnetic force, whereas the weak nuclear force is mediated by $W$ and $Z$ bosons.

Photons are bosons, not leptons; leptons are a different family of particles that includes electrons and neutrinos.

This option is incorrect. It appears to confuse the numerical value of the frequency ($1.7$) with the final energy, ignoring Planck's constant and the necessary unit conversions.

This option represents the kinetic energy in Joules ($1.3 \times 10^{-19}$ J), not electron-volts. To obtain the correct answer in eV, you must divide this value by the elementary charge ($1.60 \times 10^{-19}$ J/eV).

This value is extremely small and physically unrealistic for the kinetic energy of a photoelectron in this context. It likely results from an arithmetic error or incorrect formula application.

This describes John Dalton's early atomic theory, which viewed atoms as indivisible spheres, rather than the internal structure proposed by Bohr.

This describes Rutherford's planetary model. While similar, it fails to include Bohr's key innovation: that electrons are restricted to specific, quantized orbits.

This describes J.J. Thomson's "Plum Pudding" model, which was disproved by Rutherford before Bohr developed his model.

White light passing through a prism demonstrates dispersion and refraction, which are phenomena explained by the wave nature of light and its varying wavelengths.

Diffraction is the bending of light as it passes through a slit, which is a classic characteristic of waves rather than particles.

Interference patterns are created by the superposition of overlapping waves, providing foundational evidence for the wave model of light.