Download App

Science Answer the questions.[Phy-3M]

MODEL PAPER - 7 [2026] · CBSE STD 10 (CBSE - English Medium). 3 questions.

Questions

Answer the questions.[Phy-3M]

🎯

Test yourself on this topic

3 questions · timed · auto-graded

Question 13 Marks
Observe the following incomplete ray diagram of an object where the image A'B' is formed after refraction from a convex lens.
Image
On the basic of above information fill in the blanks.
i. The position of object AB would have been...
ii. Size of the object would have been ... than the size of image.
Answer
i. The position of object AB would have been beyond $2 F_1$.
Image
ii. Size of the object would have been bigger than the size of image.
View full question & answer→
Question 23 Marks
When one enters a less lighted room from a place of intense light, he is not able to see anything for sometime, but after sometime the things become somewhat visible. Explain how this happens?
Answer
When we are in bright sunlight the aperture of the pupil would be small to regulate the amount of light entering the eye preventing glare, discomfort and damage to eyes. As we enter a dark room less amount of light would enter our eyes due to small size of pupil, and we won't be able to see objects clearly. It takes some time to regulate the size of the pupil through iris. Hence, it requires some time to see things.
View full question & answer→
Question 33 Marks
The image formed by a spherical mirror is real, inverted and is of magnification -2. If the image is at a distance of 30 cm from the mirror, where is the object placed? Find the focal length of the mirror. List two characteristics of the image formed if the object is moved 10 cm towards the mirror.
Answer
Image distance, v = - 30 cm
Magnification, m = - 2
Magnification produced by a mirror,
$m=-\frac{v}{u} $
$-2=-\frac{(30)}{u} $
$u=-15\ cm$
Now, using mirror formula $\frac{1}{f}=\frac{1}{v}+\frac{1}{u}$
$\frac{1}{f}=-\frac{1}{30}-\frac{1}{15} $
$\frac{1}{f}=\frac{-1-2}{30} $
$\frac{1}{f}=\frac{-3}{30}=-\frac{1}{10} $
$f=-10\ cm$
If the object is shifted 10 cm towards the mirror then, $u =-5\ cm$, i.e., object is between pole and focus, thus image formed will be virtual, erect and magnified.
View full question & answer→
Generate Paper FreeAll MODEL PAPER - 7 [2026] topics
Answer the questions.[Phy-3M] - Science STD 10 Questions - Vidyadip