The de-Broglie's wavelength of an electron in the $4^{th}$ orbit is . . . . . . . . $\pi a_0$. ($a_0 =$ Bohr's radius)

The following plot represents the de-Broglie wavelength $(\lambda)$ as a function of $\frac{1}{\sqrt{K.E.}}$ for two particles $A$ and $B$. Identify the correct relation between their masses ($m_A$ and $m_B$).

An electron has kinetic energy $2.8 \times 10^{-23} \ J$. The de-Broglie wavelength will be nearly $(m_e = 9.1 \times 10^{-31} \ kg)$.

$A$ cricket ball of $0.5 \ kg$ is moving with a velocity of $100 \ m/s$. The wavelength associated with its motion is

Calculate the wavelength of an electron moving with a velocity of $2.05 \times 10^{7} \,m s^{-1}$.

Which of the following represents the de Broglie equation?