Given :
The focal length of a concave mirror is 18 cm.
To Find :
The radius of curvature of the concave mirror.
Solution :
We know,

Therefore, the radius of curvature of concave mirror is 36 cm.
Hence, this is the required solution.
Answer:
Explanation:
θ( p ) + θ( r ) = 90
θ (r) = angle of refraction and θ ( p ) is polarising angle.
given θ ( r ) = 31.8
θ ( p ) = 90 - 31.8 = 58.2 degree
ii ) Tanθ ( p ) = n ( refractive index ) = Tan 58.2 = 1.6
It is an example of balanced force.
hope this helps. good luck
I believe the answer is A