Equal masses of substances A, B and C, each at its melting point, take 5 minutes, 7 minutes and 3 minutes respectively to melt when heated at the same rate. Which has the highest specific latent heat of fusion?

(a) A

(b) B

(c) C

(d) All are equal

Complete the following by choosing the correct answers from the bracket: (a) A car is moving in uniform circular motion. The direction of friction between the tyres and the path is ............... [towards the centre / tangential to the path]. (b) When a ray of light passes from a denser to a rarer medium, its wavelength ............... [decreases / increases]. (c) The lid of a calorimeter minimises heat loss by ............... [convection / radiation]. (d) Quality of sound depends on its ............... [amplitude / waveform]. (e) A substance whose resistance becomes almost negligible at a temperature near absolute zero is called a ............... [semiconductor / superconductor]. (f) ............... radiation deviates minimum in a magnetic field [Alpha / Beta].

The given graph represents the cooling curve of a liquid. (a) State the freezing temperature of the liquid. (b) Name the phase change happening at the region QR. (c) In which state (solid / liquid) does the above substance liberate heat at a faster rate? Justify.

(a) Atmospheric temperature after a hailstorm is greater than the temperature during the hailstorm. State True or False. (b) Which thermal physical quantity of a frying pan changes by making its base heavier? (c) State the principle of Calorimetry.

When the length of a stretched metallic wire is doubled, its specific heat: (a) becomes double (b) becomes four times (c) becomes one-fourth (d) remains the same

A metal piece of thermal capacity 40 J K−1 absorbs 800 J of heat. Calculate the rise in the temperature of this metal piece.

A metal piece of mass 5 g has thermal capacity 2.5 J K⁻¹. If the mass of the metal is tripled, then its specific heat capacity will be : (a) 7.5 J K⁻¹ (b) 2.5 J K⁻¹ (c) 1.5 J g⁻¹ K⁻¹ (d) 0.5 J g⁻¹ K⁻¹

Specific heat capacity of a substance X is 1900 J kg−1 °C−1 means: (a) Substance X absorbs 1900 J for 1°C rise in temperature (b) 1 kg of substance X absorbs 1900 J heat for 1°C rise in temperature (c) 1 kg of substance X absorbs 1900 J heat to increase the temperature (d) 1 kg of substance X absorbs 1900 J heat to cool down by 1°C

Each of the substances given below is supplied with same amount of heat. Which one will attain the highest temperature? Substance Specific heat capacity (cal/g°C) Lead 0.031 Aluminium 0.21 Copper 0.095 Iron 0.115 (a) Aluminium (b) Copper (c) Iron (d) Lead

During the melting of ice at 0°C: (a) energy is released and temperature remains constant (b) energy is absorbed and temperature remains constant (c) energy is absorbed and temperature rises (d) energy is released and temperature falls

Specific latent heat of a substance: (a) is directly proportional to the mass (b) is directly proportional to the change in the temperature (c) depends on the material (d) is inversely proportional to the mass

The graph given below shows heat energy supplied against change in temperature when no energy is lost to the surrounding. The slope of this graph will give: (a) specific heat capacity (b) specific latent heat of fusion (c) specific latent heat of vaporisation (d) heat capacity

Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C. (Specific latent heat of ice = 336 J g−1, specific heat capacity of water = 4.2 J g−1 °C−1)