Which helps in changing focal length of the lens?
Optic nerve
Cornea
Retina
Ciliary muscles
Which will we get maximum number of images?
Mirrors are placed parallel
Mirrors are placed perpendicular
Mirrors are placed at an angle 45o
Mirrors are placed at an angle 30o
Stem and prongs are the parts of :
Violin
Tuning fork
Sitar
Sonometer
Light ray which strikes the surface is called :
Normal
Incident ray
Reflected ray
both 1 and 2
The vocal cords in men are about how many long?
20 mm
2 cm
15 mm
15 cm
The loudness of the sound depends upon :
Amplitude
Frequency
Time period
Velocity
A fruit appears to be bigger in a glass of water due to :
Reflection
Total internal reflection
Defraction
Refraction
The angle in between the reflected ray and the normal drawn from the point of incidence is called :
Angle of reflection
Angle of incidence
Angle of refraction
Angle of contact
Kaleidoscope works on which principle?
Multiple refraction
Multiple interference
Multiple deflection
Multiple reflection
The lens in human eye is :
Concave lens
Convex lens
Bi concave lens
Bi convex lens
