दो धातु सतहों A और B जिनके कार्य फलन φA = 9 eV और φB = 4.5 eV हैं, उनके लिए देहली तरंगदैर्घ्य (threshold wavelengths) का अंतर nm में कितना है? (दिया गया है, hc = 1242 eV nm)

The de Broglie wavelength of an oxygen molecule at 27°C is x × 10−12 m. Find the approximate value of x. (Take Planck's constant = 6.63 × 10−34 J·s, Boltzmann constant = 1.38 × 10−23 J/K, and the mass of an oxygen molecule = 5.31 × 10−26 kg).

Particle A of mass mA = m2 moving along the x-axis with velocity v0 collides elastically with another particle B at rest having mass mB = m3. If both particles move along the x-axis after the collision, the change Δλ in the wavelength of particle A, in terms of its initial de-Broglie wavelength λ0 before the collision, is: