bhaiya!! ;)
Kuch bhool nahi gaye... holi hai aaj.... kuch rang ho jaye to acha raehga naa ;p
the circular boundary of concave mirror subtends a cone of half angle θ at its centre of curvature .The minimum value of θ for which ray incident on this mirror parallel to the principal axis suffers reflection more than one is
(a)30°
(b)45°
(c)60°
(d)75°
For minimum θ ray must incident as shown...
clearly.. angle(i)=angle(θ)
also 2i=900
i=450
θ=450
bhaiya!! ;)
Kuch bhool nahi gaye... holi hai aaj.... kuch rang ho jaye to acha raehga naa ;p