VTU Engineering Physics Solution to problems-June2012 Question Paper

1(d) λ_electron = h/Ö2meV =0.91Å

λ_object = h/mv = 6.626 × 10^-34 m

2(d) P = 1/8

3 (d) n = 1 × N_A × D/A = 2.54 × 10 ²⁸

s = n e²t /m = 1.47 × 10⁷ /Wm

4(d) e_r = 1.532

5 (d) λ = 632 nm

6 (d) N.A = 0.168   V-number = 32    Number of modes = 512

7 (d) λ = 2dsinq/n = 1.348Å   E = h²/2m_e λ² = 1.33 × 10^-17 J