Activity 11.2- Observing a Candle Flame in a Plane Mirror
Objective- To understand how a plane mirror forms an image of an object, in this case, a candle flame.
Materials Needed-
- A candle.
- A matchbox or lighter to light the candle.
- A plane mirror (a flat mirror without curvature).
- A ruler or measuring tape (optional).
Procedure-
- Set Up the Candle- Place the candle on a table and light it. Make sure it’s in a safe spot where it won’t be knocked over.
- Position the Mirror- Place the plane mirror behind the candle, standing upright. Ensure that the mirror is stable.
- Observe the Reflection- Look into the mirror and observe the image of the candle flame. Notice the characteristics of the flame as seen in the mirror.
- Measure Distances (Optional)- If using a ruler or measuring tape, measure the distance from the candle to the mirror and from the mirror to the image of the candle flame in the mirror.
Also Check – Class 7 Science -Chapter 15 – Light- Complete Notes
Also Check – Chapter 11- A Detailed Guide to the Light Activities for Class 7 Students
Core Concepts Explained-
- Image Formation by Plane Mirrors- When you look in a plane mirror, you see an image of whatever is in front of it. In this activity, the mirror forms an image of the candle flame.
- Characteristics of the Image–
- Erect- The image appears upright, just like the actual candle flame. This means it’s not upside down.
- Virtual- The image seems to be behind the mirror. You cannot project this image onto a screen because it’s not real; it’s just an optical illusion created by the mirror.
- Same Size as the Object- The image of the candle flame in the mirror appears to be the same size as the actual flame.
- Image Distance Equals Object Distance- The distance from the candle to the mirror is the same as the distance from the mirror to the image of the flame in the mirror.
Possible Questions and Answers-
Why can’t we see the image on a screen?
- The image formed by a plane mirror is virtual, which means it cannot be captured on a screen. It’s a visual effect created by the way the mirror redirects light.
Why is the image the same size as the actual flame?
- Plane mirrors reflect light without distorting it, so the size of the image remains the same as the size of the object.
Is the image inside the mirror?
- It appears to be inside the mirror, but this is an illusion. The light rays from the object are reflected in such a way that our eyes perceive the image as being behind the mirror.
Why is the image erect and not inverted?
- Plane mirrors reflect light in a way that preserves the orientation of the object. Unlike curved mirrors, they don’t flip the image upside down.
