Physics 5054 · O Level · Refraction of light

Refraction of light — practice question

A solid plastic cylinder is placed in a liquid with refractive index $1.4$. Light in the plastic cylinder meets the inner surface at an angle of incidence of $70^{\circ}$. Total internal reflection occurs. What are the values of the critical angle in the plastic and the refractive index of the plastic?

  • Acritical angle greater than $70^{\circ}$, refractive index greater than $1.4$
  • Bcritical angle greater than $70^{\circ}$, refractive index less than $1.4$
  • Ccritical angle less than $70^{\circ}$, refractive index greater than $1.4$
  • Dcritical angle less than $70^{\circ}$, refractive index less than $1.4$

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI