Advertisements
Advertisements
Question
Find the time taken by a 500 W heater to raise the temperature of 50 kg of material of specific heat capacity 960 J kg-1K-1, from 18°C to 38° C. Assume that all the heat energy supplied by the heater is given to the material.
Advertisements
Solution
Power of heater (P) = 500 W
mass of material (m) = 50 kg
Specific heat capacity of material c = 960 J kg-1K-1
Change in temperature ΔT = (38 − 18)°C = 20°C (or 20 K)
ΔQ = mcΔT
ΔQ = 50 × 960 × 20
Time taken by a heater to raise the temperature of material
`"t" = (Δ"Q")/ "P" `
`"t" = (50 xx 960 xx 20)/ 500`
t = 1920 seconds
t = 32 min
APPEARS IN
RELATED QUESTIONS
Two metallic blocks P and Q of masses in ratio 2: 1 are given the same amount of heat. If their temperature rise by the same amount, compare their specific heat capacities.
Give one example where high specific heat capacity of water is used as heat reservoir ?
A calorimeter has mass 100 g and specific heat 0.1 kcal/ kg °C. It contains 250 gm of liquid at 30°C having specific heat of 0.4 kcal/kg °C. If we drop a piece of ice of mass 10 g at 0°C, What will be the temperature of the mixture?
Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates. Most of energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10 kg of water and 0.2 g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decrease by 5°C. Specific heat capacity of water = 4200 J kg−1 °C−1 and latent heat of vaporization of water = 2.27 × 106 J kg−1.
Explain, why does a wise farmer water his fields, if forecast is forst?
A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg-1 °C-1]
Answer the following question.
Why do we generally consider two specific heats of a gas?
On supplying 100 µC of charge to a conductor, its potential rises by 5 V then capacity of the conductor is ______.
Specific heat capacity C = ______.
J/Kg °C is the unit of specific heat capacity.
