de Broglie Wavelength — Prelims Questions

An electron is accelerated through a potential difference of $100\ \text{V}$. What is its de Broglie wavelength?

A particle has a kinetic energy $E_k$. If its kinetic energy is increased to $4E_k$, how does its de Broglie wavelength change?

A proton and an alpha particle are accelerated through the same potential difference. The ratio of their de Broglie wavelengths $(\lambda_p / \lambda_{\alpha})$ is:

Which of the following statements about de Broglie waves is INCORRECT?

A thermal neutron at temperature $T$ has a de Broglie wavelength $\lambda$. If the temperature is increased to $4T$, what is the new de Broglie wavelength?

If the momentum of a particle is doubled, how does its de Broglie wavelength change?