Question

Two photons of same frequency are produced due to the annhiliation of a proton and antiproton. Wave length of the proton so produced is:

• A. (A) 1.1×10−14 m
• B. (B) 1.3×10−15 m
• C. (C) 1.7×10−17 m
• D. (D) 1.9×10−19 m

Answer 1

Answer: (B)

(B) 1.3×10−15 m

Answer 2

Explanation:
Given:Two photons of same frequency are produced due to the annhiliation of a proton and antiproton.We know that:c=3×108Mass of a proton = 1.67×10−27E=mc2Put the values in above formula.E=(2×1.67×10−27)×(3×108)2 J=3.006×10−10 JAlso We know that:2hν=E or 2hcλ=E∴λ=2hcEPut the values in above formula.=2×6.62×10−34×3×1083.006×10−10 m=1.323×10−15 mHence, the correct option is (B).