76) The spherical mirror whose reflecting surface curved outward is

A) Convex mirror
B) Concave mirror
C) Plane mirror
D) None

77) Every lens has ______ focal points

A) 2
B) 4
C) 6
D) 8

78) If a convex lens is placed in water, it’s focal length

A) Increases
B) Decreases
C) Does not change
D) None of the above

79) The type of mirror used in solar cooker is

A) Concave
B) Convex
C) Concave and Convex
D) None

80) The minimum distance of an object from the pole to obtain real image in case of a concave mirror is

A) F
B) 2F
C) 0
D)