Light Travels along a Straight Line

What is the  definition of light?

Why are we not able see a candle flame through a bent pipe?

Light travels along a _____ line.

Name two natural phenomena based on the property that light travels in straight lines.

A small source of light casts a sharp shadow on an opaque object shows 

Name the property of light by which it always travels in straight lines.

(Choose from: Rectilinear propagation/Interference)

By drawing neat diagrams define the following:
A ray of light

Write five applications of rectilinear propagation of light.

A bus driver is reversing his bus at a speed $8 \mathrm{m} {\mathrm{s}}^{-1}$. The rear view mirror of a bus is a plane mirror. The driver sees in his rear view mirror the image of a car parked behind his bus. The speed at which the image of the car appears to approach the driver of car will be 

A point object is placed in front of a plane mirror. If the object and the mirror start moving away from each other with speed $v$ along a straight line, then speed of the image with respect to mirror is 

A very narrow path of light described by a straight line drawn in the direction of propagation of light is called a _____ of light.

Light always travels in a _____.

Why should we keep mirror strips parallel to each other in periscope?
What happens if they are not parallel?
 

Describe an experiment to show that light travels in a straight line.

Give reasons for the following.
We cannot see the light from a candle flame through a bent rubber tube.

Fill in the blanks:
Light travels in a _____ line.

Explain through an activity that light travels in a straight line.

Light travels in a _____ line.

Through the bent tube, you will not be able to see the flame of the candle. This proves that

With the help of an experiment, prove that light travels in a straight line.