NCERT Solutions for Chapter: Dual Nature of Radiation and Matter, Exercise 1: MCQ

Relativistic corrections become necessary when the expression for the kinetic energy $\frac{1}{2}m{v}^2$, becomes comparable with $m{c}^2$, where $m$ is the mass of the particle. At what de Broglie wavelength will relativistic corrections become important for an electron?

Two particles $A_1$ and $A_2$ of masses $m_1, m_2(m_1>m_2)$ have the same de - Broglie wavelength. Then

The de Broglie wavelength of a photon is twice the de Broglie wavelength of an electron. The speed of the electron is $v_e=\frac{C}{100}$. Then

Photons absorbed in matter are converted to heat. A source emitting $n$ photon per second of frequency $\nu$ is used to convert $1 \mathrm{kg}$ of ice at $0^o\mathrm{C}$ to water at $0^{\mathrm{o}}\mathrm{C}$. Then, the time $T$ taken for the conversion : 

A particle moves in a closed orbit around the origin, due to a force which is directed towards the origin. The de Broglie wavelength of the particle varies cyclically between two values ${\lambda }_1$,${\lambda }_2$ with ${\lambda }_1>{\lambda }_2$ . Which of the following statement are true?