Following are the important 4 Marks Questions for SSC / 10th Class public exams for AP and Telangana students as per CCE pattern of syllabus. These questions are from the chapter of Physical Sciences, Reflection of Light at Curved Surfaces:
Q: List the materials required for conducting an experiment to find the focal length of a concave mirror. Explain the experimental process also.
A: Materials required: 1) Concave mirror 2) Candle 3) Paper screen 4) v-stand 5) Meter Scale
Procedure:
Place the concave mirror on v-stand, a candle, paper screen and meter scale as shown in the figure.
Put the candle at different distances from the mirror along the scale and by moving the screen find the position where the sharp
image is formed on the paper screen.
In each case note the distance (u) of the candle from the mirror and the respective screen distance (v) from the mirror
Tabulate the observations.
Find the average of focal lengths (f) obtained.
This average value of focal length (f) is the focal length of the concave mirror.
Part – B
I. Choose the correct answer:
1. An object is placed at 5 cm distance in front of a concave mirror of 6 cm focal length, then the nature of the image is
A) Real and inverted B) Virtual and erect
C) Virtual and inverted D) Real and erect
2. Sita is searching for light of parallel beam.
This source can help her….
A) Torch B) Candle C) Sun D) Sodium vapour lamp
3. The shape of solar cooker is
A) Concave B) Plane C) Ellipsoid D) Convex
Answers:
1-B, 2-C, 3-A.