1. Mechanics
    2. 1. Units, Dimensions and Errors
    2. Vectors and Scalars
    3. Motion in a Straight Line
    4. Projectile Motion
    5. Newton's Laws of Motion
    6. Friction
    7. Work, Energy, Power and Collision
    8. Circular motion
    9. Rotational motion
    10. Simple Harmonic Motion
    11. Gravitation
    12. Elasticity
    13. Surface Tension
    14. Fluid dynamics and Viscosity
    15. Hydrostatics
  2. Heat and Thermodynamics
    3. 16. Thermometry
    17. Thermal expansion
    18. Calorimetry, Change of State and Hygrometry
    19. Gas Laws and Kinetic theory of Gases
    20. Transmission of Heat
    21. Thermodynamics
  3. Sound and Waves
    4. 22. Wave
    23. Superposition of Waves
    24. Stationary/ Standing waves
    25. Doppler's effect and Musical sound
  4. Optics
    5. 26. Reflection of Plane and Curved Mirrors
    27. Refraction at Plane surfaces and Total internal reflection
    28. Refraction through prism and Dispersion of Light
    29. Refraction through Lenses
    30. Chromatic abberation in Lenses, Optical instruments and Human eye
    31. Velocity of Light
    32. Photometry
    33. Wave nature of Light
  5. Electrostatics
    6. 34. Charge and Force
    35. Electric Field and Potential
    36. Capacitance
  6. Electrodynamics
    7. 37. Electric current
    38. Heating Effect of Current
    39. Thermoelectricity
    40. Chemical effect of Current
    41. Meters
  7. Electromagnetism
    8. 42. Properties of Magnets
    43. Magnetic effects of Current
    44. Electromagnetic induction
    45. Alternating current
  8. Modern Physics
    9. 46. Cathode rays, Positive rays and Electrons
    47. Photoelectric effect
    48. X-rays
    49. Atomic structure and Spectrum
    50. Radioactivity
    51. Nuclear physics
    52. Semiconductor and Semiconductor devices
    53. Diode and Triode valves
    54. Logic gates
    55. Relativity and Universe
    56. Particle physics
Heat and Thermodynamics
17. Thermal expansion
1. A liquid is placed in a graduated glass cylinder. The coefficient of real expansion of the liquid is thrice that of linear expansion of the glass. On heating the level of liquid will

[IOM 2013]

  • First decreases then increases.
  • Decrease.
  • Increases.
  • Approximately remains the same.
2. The pendulum of clock is made of brass. If the clock keeps correct time at 20°C, how many seconds per day will it lose at 35°C? (α_brass = 2 × 10^-5 /°C)

[IOM 2010]

  • 12.3 sec
  • 36.9 sec
  • 24.6 sec
  • 49.2 sec
3. 'C' and 'S' are the coefficient of apparent expansion of copper and silver respectively. The coefficient of linear expansion of copper is A then that of silver is

[IOM 2009]

  • (C - 3A - S)/3
  • (C - 3A + S)/3
  • (C + 3A - S)/3
  • (C + 3A + S)/3
4. A thin copper wire of length L at 0°C is heated to t°C, then the length is increased by 0.1%. If a thin copper plate of dimension L × 2L is heated through the same range of temperature, surface area of the sheet will increase by

[IE 2010]

  • 0.8%
  • 0.4%
  • 0.2%
  • 0.1%
5. When a liquid kept in a copper vessel has its apparent expansion is 6 × 10^-5 /°C. When the same liquid is heated in steel vessel its apparent expansion is 24 × 10^-5. The linear expansivity of copper is 18 × 10^-6 /°C. Find out the linear expansivity of steel.

[IE 2013]

  • 9 × 10^-6 /°C
  • 12 × 10^-6 /°C
  • 24 × 10^-6 /°C
  • 36 × 10^-6 /°C
6. The resistance of a conductor is 15 Ω at 60°C and 20 Ω at 100°C. The resistance at 10°C is

[MOE 2012]

  • 5 Ω
  • 12.5 Ω
  • 5.4 Ω
  • 17.5 Ω
7. The resistance of a material at 20°C is 1.72 Ω. At 100°C its resistance become (given α = 0.00393 K^-1)

[KU 2010]

  • 1.58 Ω
  • 2.62 Ω
  • 22.6 Ω
  • 15.8 Ω
8. A zinc rod has a length 1 m at 0°C. Find its length at 50°C. The linear expansivity of Zinc is 26 × 10^-6 /°C.

[MOE 2014]

  • 1.013 m
  • 1.0013 m
  • 1.00013 m
  • 1.13 m
9. When two rods of different length L1 and L2 of different materials of linear expansivities α1 and α2 have same difference in length at any temperature, then

[MOE 2014]

  • L1α1 = L2α2
  • L1/α1 = L2/α2
  • L1α2 = L2α1
  • L1 + L2 = α1 + α2
10. A brass rod and lead rod each 80 cm long at 0°C are clamped together about one end with their free ends coinciding. If the whole system is placed in a steam bath, then difference in length of both rods is (α_brass = 2 × 10^-5 /°C, α_lead = 1 × 10^-5 /°C)

[MOE 2014]

  • 0.2 mm
  • 0.8 mm
  • 1.4 mm
  • 1.6 mm
11. Two spheres, one solid and other hollow, are made of same material and of same radius. If both spheres are heated to the same temperature, then expansion will be more in

[MOE 2014]

  • solid
  • hollow
  • either a or b
  • same
12. Two spheres, one solid and other hollow, are made of same material and of same radius. If same heat is given to both spheres, then expansion will be more in

[MOE 2014]

  • hollow
  • solid
  • same
  • they do not expand
13. A disc has a hole of diameter 1.5 cm at 20°C. The diameter of disc when it is heated to 150°C is (α = 1.9 × 10^-5 /°C)

[MOE 2014]

  • increase by 0.002 cm
  • increase by 0.004 cm
  • decrease by 0.002 cm
  • decrease by 0.004 cm
14. A uniform rod of 2 mm cross-section is heated from 0°C to 20°C. The coefficient of linear expansion of the rod is 12 × 10^-6 /°C and its Young's modulus is 1 × 10^11 N/m². Then energy stored per unit volume in the rod is

[MOE 2014]

  • 1440 J/m³
  • 1500 J/m³
  • 2880 J/m³
  • 5160 J/m³
15. The coefficient of cubical expansion of brass and iron are 54 × 10^-6 /°C and 36 × 10^-6 /°C respectively. If brass and iron rods show the same difference of length at all temperatures, their lengths are in the ratio of

[MOE 2014]

  • 3:2
  • 2:3
  • 9:4
  • 4:9
16. On heating a liquid of cubical expansion γ in a container having linear expansion α, the level of liquid in the container will

[MOE 2014]

  • rise
  • fall
  • remains almost stationary
  • unpredictable
17. An iron cube floats in a vessel containing mercury at 20°C. If the temperature is increased by 100°C, the cube will float

[MOE 2014]

  • lower
  • higher
  • at same level
  • lower or higher depending on mass of cube
18. The real coefficient of volume expansion of glycerin is 0.000597 per °C and the linear coefficient of expansion of glass is 0.000009 per °C. Then the apparent volume coefficient of expansion of glycerin in glass will be

[MOE 2014]

  • 0.0000606/°C
  • 0.000588/°C
  • 0.00057/°C
  • 0.00027/°C
19. Steel rails 40 m long are laid on a day when the temperature is -10°C. The space that must be left between the rails to allow for expansion at a temperature of 40°C is (coefficient of linear expansion is 12 × 10^-6 /°C)

[MOE 2014]

  • 0.012 m
  • 0.024 m
  • 0.014 m
  • 0.01 m
20. A steel tape gives correct measurement at 20°C. A piece of wood is being measured with the steel tape at 0°C. The reading is 25 cm on the tape. The real length of the piece of wood must be

[MOE 2014]

  • 25 cm
  • <25 cm
  • >25 cm
  • cannot be said
21. The density of mercury is 13.6 × 10³ kg/m³ at 0°C. If the real expansion of mercury is 18.0 × 10^-5 per °C, its density at 50°C is

[MOE 2014]

  • 13.48 × 10³ kg/m³
  • 13.72 × 10³ kg/m³
  • 13.6 × 10³ kg/m³
  • 13.40 × 10³ kg/m³
22. A thin-copper wire of length L increases in length by 1% when heated from temperature T1 to T2. What is the percentage change in area when a thin copper plate of dimensions 2L × L is heated from T1 to T2?

[MOE 2014]

  • 4%
  • 1%
  • 3%
  • 2%
23. The moment of inertia of a body is I and the coefficient of linear expansion is α. If the temperature rises by a small amount Δθ, then the change in moment of inertia is nearly

[MOE 2014]

  • αIΔθ
  • 2αIΔθ
  • 4αIΔθ
  • αIΔθ/2
24. An iron tyre is to be fitted onto a wooden wheel 1.0 m in diameter. The diameter of the tyre is 6 mm smaller than that of the wheel. The tyre should be heated so that its temperature increases by (coefficient of volume expansion of iron = 3.6 × 10^-5 /°C)

[MOE 2014]

  • 500°C
  • 167°C
  • 1000°C
  • 334°C
25. The coefficient of linear expansion is α per degree Celsius. If the temperature is measured on Fahrenheit scale instead of Celsius scale, expansion now will be

[MOE 2014]

  • α per deg F
  • (5/9)α per deg F
  • 0.5α per deg F
  • (9/5)α per deg F
26. A glass vessel just holds 50 g of a liquid at 0°C. If the coefficient of linear expansion of glass is 8 × 10^-6 /°C and the coefficient of volume expansion of the liquid is 4 × 10^-4 /°C, the mass of liquid it holds at 80°C is

[MOE 2014]

  • 46 g
  • 48 g
  • 51 g
  • 42 g
27. The brass disc fits tightly in a hole in a steel plate. To loose the disc from the hole we should

[MOE 2014]

  • heat the system
  • cool the system
  • apply strong extremely force
  • it cannot be separated
28. A metal ball immersed in alcohol weighs W1 at 0°C and W2 at 50°C. The coefficient of cubical expansion of the metal is less than that of alcohol. Assuming that density of metal is large compared to that of alcohol, it can be shown that

[MOE 2014]

  • W1 > W2
  • W1 = W2
  • W1 < W2
  • W1 = 2W2
29. A metallic piece is being weighed in a liquid whose temperature is being raised continuously. Then the apparent weight of the metallic piece

[MOE 2014]

  • decreases
  • increases
  • remains unchanged
  • changes erratically
30. A liquid with coefficient of volume expansion γ is filled in a container with coefficient of linear expansion α. If the liquid overflows on heating then

[MOE 2014]

  • γ = 3α
  • γ > 3α
  • γ < 3α
  • γ ≥ 3α
31. The loss in weight of a solid when immersed in a liquid at 0°C is W0 and at t°C it is Wt. If the cubical expansion coefficient of solid and liquid are γs and γl respectively then Wt is equal to

[MOE 2014]

  • W0 [1 + (γs - γl) t]
  • W0 [1 - (γs - γl) t]
  • W0 (γs - γl) t
  • W0 / [1 + (γs - γl) t]
32. A glass flask of volume 1 litre is completely filled with mercury at 0°C. The coefficient of cubical expansion of Hg is 1.82 × 10^-4 /°C and coefficient of linear expansion of glass flask is 10 × 10^-6 /°C. If the glass flask is heated to 100°C, then how much mercury is spilled?

[MOE 2014]

  • 160 × 10^-5 litre
  • 150 × 10^-5 litre
  • 170 × 10^-5 litre
  • 152 × 10^-5 litre
33. A clock keeps correct time at 20°C. It has a metallic pendulum. The temperature falls to 10°C. If the coefficient of linear expansion of the metal is 2 × 10^-5 /°C then the number of seconds lost or gained by the clock per day is

[MOE 2014]

  • loses 8.64 sec
  • gains 8.64 sec
  • loses 19.28 sec
  • gains 19.28 sec
34. A pendulum clock gains 5 seconds per day at 16°C and loses 15 seconds per day at 40°C. Then the clock keeps correct time at

[MOE 2014]

  • 32°C
  • 20°C
  • 24°C
  • 22°C
35. If a bimetallic strip is heated, it will

[MOE 2014]

  • bend towards the metal with lower thermal expansion coefficient
  • bends towards the metal with higher thermal expansion coefficient
  • not bend at all
  • twist itself into a helix
36. Density of a liquid decreases by 0.1%. What is the linear expansivity if temperature increased is 100°C?

[IOM 1997]

  • 3.3 × 10^-6 /°C
  • 3.3 × 10^-5 /°C
  • 10^-6 /°C
  • 9.9 × 10^-5 /°C
37. Two rods of materials A and B are of the same length. Linear expansivity of A and cubical expansivity of B are 12 × 10^-6 K^-1 and 3 × 10^-5 K^-1 respectively. If both the rods are heated from the same room temperature to 80°C, the length of the rod A will be

[MOE 2058]

  • larger than the rod B
  • double the length of rod B
  • equal to the length of the rod B
  • shorter than the length of rod B
38. What happens when water at 4°C is heated further?

[TE-06]

  • mass increases slightly
  • mass decreases slightly
  • volume increases slightly
  • volume decreases slightly
39. When water is heated from 0°C to 100°C, its volume

[MOE 2014]

  • increases
  • decreases
  • doesn't change
  • first decreases than increases
40. A vessel of volume V and linear coefficient of expansion α contains a liquid. The level of liquid does not change on heating. The volume coefficient of real expansion of the liquid is

[KU 2015]

  • 3α
  • V + α
  • V - α
  • V / (V - α)