The video tutorial explains the principle of rectilinear propagation of light, which states that light travels in a straight line in a homogeneous medium unless reflected. The concept is demonstrated through a simple experiment involving three cardboards with aligned pinholes and a candle. When the cardboards and candle are aligned, the flame is visible through the pinholes, illustrating the straight-line travel of light. Displacing any cardboard disrupts the alignment, making the flame invisible, thus confirming the principle.

What is the principle of rectilinear propagation of light?

• Light travels in a zigzag pattern in a homogeneous medium.

• Light travels in a straight line in a homogeneous medium.

• Light travels in a curved path in a homogeneous medium.

• Light travels in a circular path in a homogeneous medium.

What is the role of the homogeneous medium in the principle of rectilinear propagation?

• It absorbs the light completely.

• It allows light to travel in a curved path.

• It ensures light travels in a straight line.

• It reflects the light back.

What is the purpose of making holes in the cardboards during the experiment?

• To allow air to pass through.

• To align the cardboards in a straight line.

• To observe the light passing through them.

• To balance the cardboards.

Which of the following is NOT a part of the experiment setup?

• Three cardboards with pinholes.

• Aligning the pinholes in a straight line.

• A burning candle.

• A mirror to reflect light.

Why is it important to align the candle flame with the pinholes?

• To increase the brightness of the flame.

• To ensure the light travels in a straight line.

• To make the experiment more colorful.

• To create a shadow effect.

What happens when one of the cardboards is displaced?

• The light changes color.

• The light is still visible.

• The light becomes brighter.

• The light is not visible.

What does the experiment conclude about the nature of light?

• Light does not travel at all.

• Light travels in a straight line.

• Light travels in a circular path.

• Light can travel in any direction.