Finding Focal Length of Concave Mirror


#1

To find focal length it is advisable to:

  • (a) Wooden bench holding the lens should be fixed horizontally
  • (b) Fix lens in a stand vertically
  • © The screen should be arranged slanted
  • (d) Both (A) and (B)

#2

I think the answer should be (b). By fixing the lens in a stand vertically you can find the focal length of concave mirror.