Skip to content
Login Register

#exam practice

322 public questions tagged with this topic.

Temperature Scales and Triple Point

Which statement is incorrect regarding Torricelli’s law?

Torricelli’s law (v = 2gh) assumes non-viscous flow and neglects losses, not depending on viscosity or requiring turbulence. The incorrect statement is that it depends on fluid viscosity. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It depends on fluid viscosity. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

View Details
Bernoulli's Theorem and Applications

What is the total pressure at a depth of 2.2m in hydrogen liquid (ρ\=9.0×10−2kg/m3) with atmospheric pressure 1.01×105Pa

Total pressure: P = Pa+ρgh. Pa = 1.01×105Pa, ρ = 9.0×10−2kg/m3, g = 9.8m/s2, h = 2.2m. P = 1.01×105+9.0×10−2×9.8×2.2 = 1.01×105+1.94 = 1.0100194×105Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.01 × 10⁵ Pa. This satisfies dimensional consistency and physical conditions given, so option A is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

View Details
Bernoulli's Theorem and Applications

What is the excess pressure inside a water drop of radius 2.5mm at 20∘C? (Surface tension = 0.0727N/m)

Excess pressure: ΔP = 2Sr. S = 0.0727N/m, r = 2.5×10−3m. ΔP = 2×0.07272.5×10−3 = 58.16Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 58 Pa. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

View Details
Equation of Continuity and Flow Rate

Water (ρ\=1000kg/m3) flows horizontally at 4.2m/s with pressure 1.95×105Pa. If the speed increases to 6.5m/s, what is th

Bernoulli’s equation: P1+12ρv12 = P2+12ρv22. P1 = 1.95×105Pa, v1 = 4.2m/s, v2 = 6.5m/s, ρ = 1000kg/m3. P2 = 1.95×105+12×1000(17.64−42.25) = 1.95×105−12305 = 1.82695×105Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.83 × 10⁵ Pa. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

View Details
Equation of Continuity and Flow Rate

A sphere of radius 0.05m moves at 0.11m/s through blood (η\=2.7×10−3Pa s). What is the viscous drag force?

Stokes’ law: F = 6πηav. η = 2.7×10−3Pa s, a = 0.05m, v = 0.11m/s. F = 6×3.14×2.7×10−3×0.05×0.11 = 0.0028N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.0028 N. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

View Details