Q. 24.3( 6 Votes )
A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge is
A. blue.
B. green.
C. violet.
D. red.
Answer :
The speed of light v in a medium of refractive index n is given by:
where c is the speed of light in vacuum. Now, each colour has different refractive index in a medium. Thus, they have different speeds (except in vacuum). As the relation between speed and refractive index is inverse, the first colour to emerge should have the lowest refractive index. Red has the lowest refractive index. Hence, option (d) is correct.
Rate this question :
How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
PREVIOUSA ray of light incident at an angle on a refracting face of a prism emerges from the other face normally. If the angle of the prism is 5° and the prism is made of a material of refractive index 1.5, the angle of incidence isNEXTAn object approaches a convergent lens from the left of the lens with a uniform speed 5 m/s and stops at the focus. The imageA. moves away from the lens with a uniform speed 5 m/s.B. moves away from the lens with a uniform acceleration.C. moves away from the lens with a non-uniform acceleration.D. moves towards the lens with a non-uniform acceleration.
Related Videos
Ray Optics | Getting the basics46 mins
Master Wave Optics with Questions40 mins
Best Questions of on Spherical Mirror39 mins
Young's Double slit Experiment | Master important concepts45 mins
Concave & Convex lens44 mins
Understand Concept of Polarization40 mins
Young's Double slit Experiment | Concepts at fingertips50 mins
Young's Double Slit Experiment51 mins
Revision Quiz of 12th | Nuclear Physics71 mins
Photoelectric Effect | World of Photons45 mins
Ray Optics | Getting the basics46 minsMaster Wave Optics with Questions40 minsBest Questions of on Spherical Mirror39 minsYoung's Double slit Experiment | Master important concepts45 minsConcave & Convex lens44 minsUnderstand Concept of Polarization40 minsYoung's Double slit Experiment | Concepts at fingertips50 minsYoung's Double Slit Experiment51 minsRevision Quiz of 12th | Nuclear Physics71 minsPhotoelectric Effect | World of Photons45 minsTry our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
view all courses
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
RELATED QUESTIONS :
Between the primary and secondary rainbows, there is a dark band known as Alexandra’s dark band. This is because
Physics - ExemplarThe phenomena involved in the reflection of radio waves by ionosphere is similar to
Physics - ExemplarWhy does sun appear red at sunrise and sunset?
Physics - Board Papers