1st Year (Class 11) — Physics

Q1. The dimension of force is:

✔ Correct: A — Force = mass x acceleration, so dimensions are M x LT-2 = MLT-2.

Q2. Which pair has the same dimensions?

✔ Correct: A — Work and torque both have dimensions ML2T-2 (though they are different quantities).

Q3. The number of significant figures in 0.0050 is:

✔ Correct: B — Leading zeros do not count; 5 and the trailing 0 do - total 2.

Q4. One light year is a unit of:

✔ Correct: B — A light year is the distance light travels in one year, about 9.46 x 10^15 m.

Q5. The percentage uncertainty in a measurement is:

✔ Correct: A — Percentage uncertainty = (absolute uncertainty / measured value) x 100.

Q6. Candela is the SI unit of:

✔ Correct: B — Candela (cd) measures luminous intensity.

Q7. Which measurement is most precise?

✔ Correct: B — 4.00 cm has three significant figures, the greatest precision here.

Q8. Random errors can be reduced by:

✔ Correct: B — Averaging repeated readings reduces the effect of random errors.

Q9. The dimension of velocity is:

✔ Correct: A — Velocity = displacement/time, dimensions LT-1.

Q10. Systematic errors are caused by:

✔ Correct: B — Systematic errors come from instrument faults, zero errors or flawed procedure, and shift all readings one way.