Energy Dependence | MCQs

Explanation

Momentum (p) is proportional to velocity (v), while kinetic energy (KE) is proportional to v².

When momentum decreases by 20%, velocity decreases by 20%.

So, kinetic energy decreases by (1 - 0.8²) × 100% ≈ 36%.

Explanation

The maximum kinetic energy (K.E.) of photoelectrons depends on the frequency of the incident light, not its intensity. 

According to Einstein's photoelectric equation:

K.E. = hf - φ

where hf is the energy of the photon, which depends on its frequency (f).