WorksheetsLight
Total questions: 20
Worksheet time: 13mins
Light years are a unit of what?
Time
Speed
Distance
Luminous intensity
What is the focal length?
Length of the focus
Distance between the focus and the vertex (along the principal axis)
Distance between the focus and the center of curvature (along the principal axis)
Radius of curvature
What is the approximate speed of light in vaccum in km/s?
three million
three lakh
three crore
three thousand
I can provide an essential vitamin to your body. I can also cause skin cancer. Who am I?
Ultraviolet rays
Infrared rays
Gamma rays
Radio waves
Why are convex mirrors used in cars?
Because they provide a wider field of view compared to plain mirrors
Because they are cheaper and easier to manufacture
Because they enlarge the vehicles behind, causing them to be observed more clearly
All of the above
(a) are found in headlights.
(A) Warnings are often found in car mirrors.
(B) Convex mirrors show objects closer than they appear.
Both (A) and (B) are true and (B) is a correct explanation for (A)
Both (A) and (B) are true but (B) is not a correct explanation for (A)
(A) is true but (B) is false
(B) is true but (A) is false
What is the principal axis?
A line which passes through the centre of a mirror
A line along which the focal length is measured
All of the above
'Light always travels in a straight line'
What is the name of this property?
Rectilinear propagation of light
Conservation of light energy
Straight propagation of light
None of the above
Which of the following is the correct sequence of colours in a rainbow?
Red, orange, yellow, green, blue, indigo, violet
Red, orange, yellow, green, blue, indigo, white
Red, orange, yellow, green, indigo, blue, violet
Violet, indigo, blue, green, yellow, orange, red
What is the point where the reflected rays of light meet?
Centre of curvature
Aperture
None of the above
Which of the following can release its own light?
Moon
Planets
Stars
All of the above
(a) mirrors are used in security mirrors.
(a) causes a pencil to appear bent in water.
(a) causes a rainbow.
Why do stars twinkle?
The rate of combustion of fuel in the star fluctuates
The inconsistency in the density of the atmosphere of the earth causes refraction
None of the above
Ultraviolet light can be detected by:
(a)
When reflection takes place on a smooth surface, angle of (a) is equal to the angle of reflection.
Concave mirrors are used in:
Dentist's mirror
Search light
Security mirror
Regular vanity mirrors
The point where the principal axis touches the surface of the mirror is known as:
(a)
