Question

Let us hold a concave mirror in our hand and direct its reflecting surface towards the sun. Direct the light reflected by the mirror on to a sheet of paper held close to the mirror. Move the sheet back and forth till we find a bright, sharp spot of light on the paper sheet. Hold on the mirror and the paper in the same position for some time .We observe that the paper at first begins to burn producing smoke and eventually it may even catch fire . This activity shows the converging action of concave mirror. The heat produced due to concentration of sunlight ignites the paper.
On what physical phenomenon is action of a mirror is based? Define it.
Name the point where you observe bright sharp spot on the paper. Define it.
What is the formula for magnification obtained with amirror?
Ratio of height of image to height ofobject
Double the focallength.
Inverse of the radius ofcurvature.
Inverse of the objectdistance
Draw a ray diagram to show the converging action of a concave mirror.
Can the same activity be performed by a convex mirror too? Give reason.​

Answer 1

Answer:

The rays from sun after reflection from the mirror, shall converge at focus. Holding  a sheet of paper at the focus, may cause it to burn if the reflected rays are very strong but if a sheet of paper is held very close to the mirror, it will lie in between the pole and the focus and hence shall only warm up.

Hope this helps.

Answer 2

The development relies on the reflection of sunshine

• Student is exploitation convergence form of mirror that's concave mirror
• Yes, he will live the approximate the focal distance from this activity as paper can burn once it's unbroken at the main focus of the mirror
• Move the sheet back and forth bit by bit, till you discover a bright sharp spot of sunshine on the paper
• $\frac{1}{f} = \frac{1}{u} + \frac{1}{v}$ that is formula for magnification.
• The quantitative relation of the peak of a picture to the peak of associate degree object referred to as magnification.
• The magnification equation relates the quantitative relation of the image distance and object distance to the quantitative relation of the image height (hi) and object height (ho).
• If radius of curvature of a mirror is doubled, its focal distance is halved.
• Reason Radius of curvature = two times the focal distance.
• The same activity are often done exploitation convex mirror however It shows completely different values of focal distance.

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