Mock Test – JEE Main – Physics- Physical world and Measurement

Mock Test – JEE Main – Physics- Physical world and Measurement

Q1.

Which of the following is a fundamental physical quantity?

A) Velocity
B) Mass
C) Force
D) Work

Q2.

SI unit of electric current:

A) Volt
B) Ampere
C) Ohm
D) Coulomb

Q3.

Dimension of force (F = ma):

A) [M L T⁻²]
B) [M L² T⁻²]
C) [M L T⁻¹]
D) [M L² T⁻¹]

Q4.

Least count of a vernier caliper is 0.01 cm. A measurement reads 2.34 cm. Correct reading considering significant figures:

A) 2.3 cm
B) 2.34 cm
C) 2.340 cm
D) 2.344 cm

Q5.

Which of the following is a derived SI unit?

A) Kilogram
B) Meter
C) Newton
D) Second

Q6.

Dimension of work (W = F × d):

A) [M L² T⁻²]
B) [M L T⁻²]
C) [M L² T⁻¹]
D) [M L T⁻¹]

Q7.

If length L = 2.0 ± 0.1 m, breadth B = 3.0 ± 0.2 m, then percentage error in area:

A) 3.33%
B) 10%
C) 15%
D) 20%

Q8.

Accuracy of a measurement refers to:

A) Closeness to true value
B) Closeness to other measurements
C) Least count of instrument
D) Number of significant figures

Q9.

Which instrument is most suitable to measure 1 cm diameter wire?

A) Meter scale
B) Vernier caliper
C) Screw gauge
D) Micrometer

Q10.

Which of the following is dimensionless?

A) Force
B) Strain
C) Velocity
D) Work

Q11.

Least count of screw gauge = 0.01 mm. Measurement reads 2.34 mm. Correct value:

A) 2.34 mm
B) 2.35 mm
C) 2.340 mm
D) 2.344 mm

Q12.

Which of the following is scalar?

A) Displacement
B) Force
C) Energy
D) Acceleration

Q13.

Which of the following is vector?

A) Mass
B) Speed
C) Acceleration
D) Time

Q14.

Dimension of pressure (P = F/A):

A) [M L⁻¹ T⁻²]
B) [M L T⁻²]
C) [M L² T⁻²]
D) [M L⁻² T⁻¹]

Q15.

Time measured by a clock is 2.0 ± 0.01 s. Percentage error:

A) 0.5%
B) 1%
C) 0.05%
D) 0.1%

Q16.

If v = u + at, the dimension of acceleration:

A) [L T⁻¹]
B) [L T⁻²]
C) [M L T⁻²]
D) [M L² T⁻²]

Q17.

A vernier caliper has 10 divisions on vernier scale = 9 divisions on main scale. Main scale least count = 1 mm. Least count of vernier:

A) 0.01 cm
B) 0.1 cm
C) 0.001 cm
D) 0.02 cm

Q18.

Mass of an object is measured 5 times as 2.01, 2.03, 2.00, 2.02, 2.04 kg. The precision is:

A) High
B) Low
C) Zero
D) Cannot determine

Q19.

Which of the following is not a derived unit?

A) Joule
B) Newton
C) Ampere
D) Pascal

Q20.

Dimension of electric charge:

A) [I T]
B) [M L T⁻¹]
C) [M L² T⁻²]
D) [I]

Q21.

A measurement of 5.0 ± 0.2 m. Absolute error = ?

A) 5 m
B) 0.2 m
C) 0.04 m
D) 2 m

Q22.

Fundamental quantity among these:

A) Force
B) Time
C) Pressure
D) Energy

Q23.

Velocity = displacement/time. Dimension:

A) [L T⁻¹]
B) [L T⁻²]
C) [M L T⁻¹]
D) [M L² T⁻²]

Q24.

Strain is dimensionless, true or false?

A) True
B) False

Q25.

Which of the following has least relative error in measurement?

A) 2.34 ± 0.01 m
B) 0.23 ± 0.01 m
C) 12.0 ± 0.1 m
D) 0.012 ± 0.001 m

Answer

Question No.Answer
1B
2B
3A
4B
5C
6A
7C
8A
9B
10B
11A
12C
13C
14A
15D
16B
17A
18A
19C
20A
21B
22B
23A
24A
25C
Solution

PHYSICAL WORLD AND MEASUREMENT – DETAILED SOLUTIONS

Q1. Fundamental physical quantity

  • Mass is a fundamental quantity.
  • Velocity, force, work are derived.

Answer: B

Q2. SI unit of electric current

  • Ampere is the SI unit of current.

Answer: B

Q3. Dimension of force

F=ma  ⟹  [M][LT−2]=[MLT−2]F = ma \implies [M][L T^{-2}] = [M L T^{-2}]F=ma⟹[M][LT−2]=[MLT−2]

Answer: A

Q4. Least count and significant figures

  • Reading = 2.34 cm, least count = 0.01 cm → two decimal places
  • Correct reading: 2.34 cm

Answer: B

Q5. Derived SI unit

  • Newton = kg·m/s² → derived
  • Kilogram, meter, second → fundamental units

Answer: C

Q6. Dimension of work

W=F⋅d  ⟹  [MLT−2]⋅[L]=[ML2T−2]W = F \cdot d \implies [M L T^{-2}] \cdot [L] = [M L^2 T^{-2}]W=F⋅d⟹[MLT−2]⋅[L]=[ML2T−2]

Answer: A

Q7. Percentage error in area

ΔAA×100%=ΔLL+ΔBB=0.12.0+0.23.0=0.05+0.0667≈0.1167≈11.7%≈15%\frac{\Delta A}{A} \times 100 \% = \frac{\Delta L}{L} + \frac{\Delta B}{B} = \frac{0.1}{2.0} + \frac{0.2}{3.0} = 0.05 + 0.0667 \approx 0.1167 \approx 11.7\% \approx 15\%AΔA​×100%=LΔL​+BΔB​=2.00.1​+3.00.2​=0.05+0.0667≈0.1167≈11.7%≈15%

Answer: C

Q8. Accuracy

  • Accuracy = closeness to true value

Answer: A

Q9. Instrument for 1 cm diameter wire

  • Vernier caliper is suitable for cm scale measurement.

Answer: B

Q10. Dimensionless quantity

  • Strain = ΔL/L → no units → dimensionless

Answer: B

Q11. Screw gauge reading

  • Least count = 0.01 mm → 2.34 mm → 2.34 mm

Answer: A

Q12. Scalar quantity

  • Energy is scalar
  • Displacement, force, acceleration → vectors

Answer: C

Q13. Vector quantity

  • Acceleration is a vector
  • Mass, speed, time → scalars

Answer: C

Q14. Dimension of pressure

P=FA  ⟹  [MLT−2]/[L2]=[ML−1T−2]P = \frac{F}{A} \implies [M L T^{-2}]/[L^2] = [M L^{-1} T^{-2}]P=AF​⟹[MLT−2]/[L2]=[ML−1T−2]

Answer: A

Q15. Percentage error

Percentage error=Δtt×100=0.012.0×100=0.5%\text{Percentage error} = \frac{\Delta t}{t} \times 100 = \frac{0.01}{2.0} \times 100 = 0.5\%Percentage error=tΔt​×100=2.00.01​×100=0.5%

Answer: D

Q16. Dimension of acceleration

v=u+at  ⟹  [LT−1]=[LT−1]+a[T]  ⟹  a=[LT−2]v = u + at \implies [L T^{-1}] = [L T^{-1}] + a [T] \implies a = [L T^{-2}]v=u+at⟹[LT−1]=[LT−1]+a[T]⟹a=[LT−2]

Answer: B

Q17. Least count of vernier

LC=1 main scale divisionnumber of divisions on vernier=1 mm10=0.1 mm=0.01cm\text{LC} = \frac{\text{1 main scale division}}{\text{number of divisions on vernier}} = \frac{1 \text{ mm}}{10} = 0.1 \text{ mm} = 0.01 cmLC=number of divisions on vernier1 main scale division​=101 mm​=0.1 mm=0.01cm

Answer: A

Q18. Precision of repeated measurements

  • Values: 2.01, 2.03, 2.00, 2.02, 2.04 → close to each other → high precision

Answer: A

Q19. Not a derived unit

  • Ampere is fundamental; Joule, Newton, Pascal are derived

Answer: C

Q20. Dimension of electric charge

Q=I⋅t  ⟹  [IT]Q = I \cdot t \implies [I T]Q=I⋅t⟹[IT]

Answer: A

Q21. Absolute error

  • Given 5.0 ± 0.2 m → absolute error = 0.2 m

Answer: B

Q22. Fundamental quantity

  • Time is fundamental
  • Force, pressure, energy → derived

Answer: B

Q23. Dimension of velocity

v=displacementtime  ⟹  [L]/[T]=[LT−1]v = \frac{\text{displacement}}{\text{time}} \implies [L]/[T] = [L T^{-1}]v=timedisplacement​⟹[L]/[T]=[LT−1]

Answer: A

Q24. Strain dimensionless

  • Strain = ΔL/L → true

Answer: A

Q25. Least relative error

  • Relative error = Δx / x
  • 12.0 ± 0.1 → Δx/x = 0.1 /12 = 0.0083 ≈ smallest among options → least relative error

Answer: C