Which of the following is a condition required for the total internal reflection of light to occur on the glass-air boundary?
The angle of incidence is equal to the critical angle
The angle of incidence is smaller than the critical angle
The angle of incidence is greater than the critical angle
What changes to cause a refraction to occur?
Speed of the wave
Frequency of the wave
Amplitude of the wave
Which of the following diagrams correctly shows the path of light being totally internally reflected in an optical fibre?
Calculate the time taken for an optical fibre to transmit an infrared signal over a distance of 400 km (remember infrared is part of the electromagnetic spectrum and travels at a speed of 3 × 108 m/s).
1.3 × 10-3 s
1.3 × 10-6 s
1.3 × 10-9 s
What is used in endoscopy?
Gamma rays
Optical fibres
X-rays
How are waves moving when total internal reflection occurs?
From a less dense medium into a more dense medium
From a more dense medium into a less dense medium
Along the normal
Which of the following diagrams shows the path of light hitting the boundary between glass and air at an angle that is greater than the critical angle?
Which of the following is an advantage of using optical fibres over satellites in long distance communication?
The signals in optical fibres suffer less interference
Optical fibres can be used to communicate over a greater distance
The signal travels faster through an optical fibre
In which of the following are optical fibres used?
Medical examinations
Mobile communications
Cancer treatment
When light hits a glass to air boundary at an angle that is greater than the critical angle, it undergoes what kind of reflection?
Internal reflection
Total internal reflection
Total reflection