Two are true, one is not

Exercise and reference answers

Questions

1. False statement

   It happens going from air into water

   Statements

   1. Total internal reflection goes denser to rarer
   2. It needs i greater than the critical angle
   3. It happens going from air into water

2. False statement

   Both mirrors have positive focal length

   Statements

   1. Both mirrors have positive focal length
   2. A convex mirror has positive focal length
   3. A concave mirror has negative focal length

3. False statement

   1 D equals 1 metre

   Statements

   1. Power is the reciprocal of focal length
   2. 1 D equals 1 metre
   3. The dioptre is the SI unit of power

Explanation