Question 9
Modern PhysicsThe energy E of a photon and its wavelength are related by Eλ=X. The numerical value of X is [h=6.63 × 10−34 Js, c=3 × 108 ms−1]
- A.1.99 × 10−27.
- B.6.60 × 10−26.
- C.1.99 × 10−25.
- D.6.60 × 10−28.
Show the answer and explanation
Answer: C (1.99 × 10−25.)
Explanation
E = hc/λ, so Eλ = hc = 6.63 × 10−34 × 3 × 108 = 1.99 × 10−25 J m.