A bullet of mass 40 g is traveling at a speed of 1.0 km/s. Its de-Broglie wavelength would be

$1.7 × 10^{-35} m$

The correct answer is Option (1) → $1.7 × 10^{-35} m$

Given:

Mass $m = 40 \, \text{g} = 0.040 \, \text{kg}$

Speed $v = 1.0 \, \text{km/s} = 1000 \, \text{m/s}$

Planck's constant $h = 6.63 \times 10^{-34} \, \text{Js}$

de-Broglie wavelength formula:

$\lambda = \frac{h}{mv}$

$\lambda = \frac{6.63 \times 10^{-34}}{0.040 \times 1000}$

$\lambda = \frac{6.63 \times 10^{-34}}{40} = 1.6575 \times 10^{-35} \, \text{m}$