A light ray in air enters and passes through a block of glass. What can be started with regard to its speed after it emerging from the block?
Speed is less than when in glass
Speed is less than before it entered glass
Speed is same as that in glass
Speed is same as that before it entered glass
If a lens gives a positive magnification greater than unity, then what type of image does it indicate?
Real and inverted image having smaller size than the object
Virtual and upright image having larger size than the object
Real and upright image having smaller size than the object
Virtual and inverted image having larger size than the object
Which list is the correct primary color list?
blue, green, yellow
blue, red, yellow
red, blue, green
white, black, grey
Through which part of the lens the ray of light without suffering deviation and in which position is the object placed if a convex lens always gives real image?
Optical centre, focus
pole, focus
focus,beyond centre of curvature
Optical centre, beyond centre of curvature
Which of the following is false with regard to optical radiation?
the wavelengths of visible light lie between 400nm and 780nm
ultraviolet A has a shorter wavelength than ultraviolet C
the human lens is better at absorbing shorter than longer wavelengths
eclipse burn is caused by infrared radiation
Which of the following describes the best, what will happen to a light ray incident on an air- to- glass - boundary?
Total reflection
Total Transmission
Partial reflection, partial transmission
Partial reflection, total transmission
An object is placed 12cm away from a convex lens whose focal length is 10cm. What will the nature of the image formed?
Virtual and enlarged
Virtual and reduced in size
Real and reduced in size
Real and enlarged
Sunsets often have a reddish- orange color associated with them. Which phenomenon does the attribute?
Polarization
Diffraction
Dispersion
Refraction
A Convex lens forms a real and inverted image of a needle at a distance of 25cm from a lens. If the image is the same size as that of the needle, where should the needle be placed in front of the lens? Calculate the power of the lens.
the needle be placed at a distance of 25cm in front of the lens and the power is +0.08D
the needle be placed at a distance of 12.5cm in front of the lens and the power is +0.08D
the needle be placed at a distance of 25cm in front of the lens and the power is +8D
the needle be placed at a distance of 12.5cm in front of the lens and the power is +8D
Which of the following describes the best image for a thin converging lens that forms whenever the object is at a distance less than the focal length from the lens?
Inverted, enlarged and real
Upright,enlarged and virtual
Upright, reduced and virtual
Inverted, reduced and real
