CBSE Class 10 Science Sample Paper 2026–27: Physics MCQs Q30–32 Explained
Attempt Physics questions Q30–32 in the official Science sample paper, then use this 5:46 walkthrough to review the reasoning. Choose a chapter below.
5:46 · No login needed · No automatic playback
What this episode covers
The three Physics objective questions Q30–32 in Section C: focal length, electrical power and apparent depth. Q33 onward and the rest of the paper are outside this episode. Safety: never look at the Sun directly or through a lens. Concentrated sunlight can injure eyes and burn materials. The ray diagram is a model; practical work needs teacher supervision and brief exposure.
These are original TutorMax explanations of the official paper, not an official CBSE video. Narration uses text-to-speech. The readable notes summarise the reasoning; they are not a verbatim transcript. Use the official marking scheme when reviewing your paper.
Keep the reasoning, not just the answer letter
Attempt the official question before watching its explanation. Afterwards, close the answer and explain the key idea in your own words. If you can only remember the letter, revisit the relevant note.
Q30 · Finding focal length
For a distant source, rays reaching a small convex lens are approximately parallel. A sharp image forms near the focus. Measure along the principal axis from optical centre to screen, not the bright-spot width or lens thickness. The solar image has a finite size. Never look at the Sun through a lens.
Revisit this explanation on YouTube ↗Q31 · Power, voltage and current
In this Class 10 model, P = VI, so I = P/V. A watt divided by a volt gives an ampere. Check the answer by multiplying voltage and current to recover power; this catches a reversed division. This is a calculation, not a mains experiment.
Revisit this explanation on YouTube ↗Q32 · Apparent depth and refraction
Oblique light travelling from water to air bends away from the normal. The eye traces the emerging rays backwards to a shallower virtual image. The real coin does not move; dashed extensions are not real light paths. A ray along the normal has no angular deviation.
Revisit this explanation on YouTube ↗Can you use the idea in a changed example?
These questions are original TutorMax practice, not official CBSE questions. Try them without the video or notes. They check a few ideas from this episode, not whole-subject readiness.
Fresh practice 1
In the same Class 10 model, an appliance uses 900 W at 225 V. Calculate the current and check the unit and result.
Check the reasoning
I = 900/225 = 4 A. Check: 225 V × 4 A = 900 W. Revisit Q31 if you divided voltage by power. Do this on paper; do not test mains equipment.
Fresh practice 2
A coin's image appears closer to the water surface. Has the coin moved? What do the backward ray extensions represent?
Check the reasoning
The coin stays at its real depth. Backward extensions of the emerging rays locate a virtual image; they are not actual light paths inside the water. Revisit Q32 if you treated the dashed lines as physical rays.
Choose your next step
If an idea was unclear, revisit the concept guide. If the idea makes sense but you misread the options, return to that video chapter and explain why the tempting choice fails. Then use the paper-review guide to plan your next attempt.
Video and authored source package checked 6 October 2026.