TS EAMCET 18-July-2022 Shift 2 Solved Paper

Given, power of incident beam,
P=10W
Energy of EM wave,
E=‌

hc

λ

or Power or EM wave,
‌P=‌

E

t

=‌

hc

λt

‌P=‌

h

λ

⋅(‌

c

t

)‌‌‌⋅⋅⋅⋅⋅⋅⋅(i)
But we know that, de-Broglie wavelngth
λ=‌

h

p

.
where, p= momentum
⇒‌‌p=‌

h

λ

‌‌‌⋅⋅⋅⋅⋅⋅⋅(ii)
From Eqs. (i) and (ii), we have
P=p‌

c

t

=‌

p

t

⋅c=Fc
⇒‌‌F=‌

P

c

∴ Total effective force =F‌absorbed ‌+F‌reflected ‌
‌=70%‌ of ‌‌

P

c

+2×30%‌ of ‌‌

P

c

‌=0.7‌

P

c

+0.6‌

P

c

‌=1.3‌

P

c

=‌

1.3×10

3×108

=4.33×10−8N