VCAA Physics How has understanding about the physical world changed?

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.

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.

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 calculation incorrectly treats the given 125 m as the proper length ($L_0$) and solves for the contracted length. Since the observer on the spaceship is at rest relative to it, they measure the proper length, which must be longer than the contracted length measured by the outside observer.

This answer results from omitting the square root in the Lorentz factor calculation, dividing 125 by $(1 - 0.3^2)$ instead of $\sqrt{1 - 0.3^2}$.

This value is incorrect and does not align with the standard length contraction formula. It likely results from a calculation error or misapplication of the Lorentz factor $\gamma$.

Stability is determined by binding energy per nucleon, not total binding energy, so we cannot determine which nucleus is more stable without knowing their nucleon numbers.

Stability depends on binding energy per nucleon, which cannot be determined from total binding energy alone.

Since nucleus X has a greater binding energy, it must have a greater mass defect than Y, not the other way around.

This describes gamma rays specifically, which are just one type of high-energy electromagnetic radiation, rather than the general definition for all electromagnetic radiation.

This defines ionizing radiation, which includes high-energy particles (like alpha and beta particles) in addition to waves, and excludes non-ionizing electromagnetic radiation like radio waves and visible light.

While this correctly describes the mechanism of generation and the geometry of an electromagnetic wave, Option D provides the more complete and formal definition of the radiant energy itself and its propagation characteristics.

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.

Incorrect. While an electron is a lepton, it has the exact same mass as its antiparticle, the positron.

Incorrect. An electron is a lepton, not a baryon; baryons are composite particles made of three quarks (e.g., protons).

Incorrect. Electrons are leptons and do not experience the strong nuclear force, unlike mesons which are hadrons.