Specific Heat

IMPORTANT

Specific Heat: Overview

This topic covers concepts, such as, Heat Capacity, Specific Heat Capacity, Variation of Specific Heat Capacity of Water with Temperature & Specific Heat of a Gaseous Mixture etc.

Important Questions on Specific Heat

MEDIUM
IMPORTANT

The molar heat capacity of water at constant pressure is  75J K1 mol1. When 1kJ of heat is supplied to 100g of water, which is free to expand, the increase in temperature of water is

                               

EASY
IMPORTANT

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio CPCV  for the gas is x2. Find x.

MEDIUM
IMPORTANT

Two different liquids of same mass are kept in two identical vessel, which are placed in a freezer that extracts heat from them at the same rate causing each liquid to transform into a solid. The schematic figure below shows the temperaure T vs time t plot for the two materials. We denote the specific heat in the liquid states to be CL1 and CL2 for materials 1 and 2 respectively, and latent heats of fusion U1 and U2 respectively.

Question Image

Choose the correct option.

MEDIUM
IMPORTANT

Heat (Q) is supplied to a solid to raise its temperature (T) across its melting point TM and boiling point TB. Which of the following graphs correctly represents the relation between heat supplied and temperature ?

EASY
IMPORTANT

200 g water is heated from 40 oC to 60 oC . Ignoring the slight expansion of water, the change in its internal energy is close to (Given specific heat of water =4184 J/kg/K):

HARD
IMPORTANT

A current carrying wire heats a metal rod. The wire provides a constant power P to the rod. The metal rod is enclosed in an insulated container. It is observed that the temperature T in the metal rod changes with time t as:

Tt=T01+βt1/4

where β is a constant with appropriate dimension while T0 is a constant with dimension of temperature. The heat capacity of the metal is:

EASY
IMPORTANT

A person weighing 50 kg takes in 1500 kcal diet per day. If this energy were to be used in heating the body of person without any losses, then the rise in his temperature is (specific heat of human body =0.83 cal g-1 -1 )

MEDIUM
IMPORTANT

Amongst object A and B, if the specific heat of object A is less than of object B, then 

MEDIUM
IMPORTANT

Calorie is the unit of which physical quantity?

MEDIUM
IMPORTANT

Calorie is the unit of which physical quantity?

EASY
IMPORTANT

What is the SI unit of heat?

MEDIUM
IMPORTANT

A cube of lead of 500 g at 25 °C is supplied with a 3225 J heat. Find the final temperature (in degree Celsius) of the lead cube. (Take, specific heat of lead is 0.129 Jg °C

MEDIUM
IMPORTANT

Calculate the heat energy (in joules) to raise the temperature of 5 kg of water from 20 °C to 100 °C. (Take specific heat of water, sw=4.2×103 J kg-1 K-1)

MEDIUM
IMPORTANT

The amount of heat required to raise the temperature of 1 kg mass of water through 1 K is called its

MEDIUM
IMPORTANT

Specific heat of a substance is given by S=(1+2T) J kg-1 K-1, find out amount of heat required to raise the temperature of 2 kg substance from 10°C to 20°C.

MEDIUM
IMPORTANT

The number of degrees of freedom of a gas whose specific heat capacity at constant pressure is 33.24 J mol-1 K-1, is
(universal gas constant =8.31 J mol-1 K-1 )

HARD
IMPORTANT

The ends of a uniform metal rod of length 100 cm and area of cross-section 2 cm2 are maintained at 0 °C and 100 °C. At the mid-point of the rod, heat is supplied at a constant rate of 40 J s-1. If the temperature gradient on the higher temperature side of the rod in steady state is 50x °C m-1, then the value of x is (Thermal conductivity of the metal =400 J s-1 m-1 K-1)

MEDIUM
IMPORTANT

A copper wire 2 m long is stretched by 1 mm. If the energy stored in the stretched wire is converted to heat, calculate the rise in temperature of the wire. (Given: Y=12×1011 dyne cm-2, Density of copper =9 g cm-3 and Specific heat of copper =0.1 calg-1 C-1:

HARD
IMPORTANT

20 gm ice at -10°C is mixed with m gm steam at 100°C. The minimum value of m so that finally all ice and steam converts into water is,

(Use, sice=0.5 cal gm-1 °C, swater=1 cal gm-1 °CL(melting)=80 cal gm-1 and L (vaporization)=540 cal gm-1.)

HARD
IMPORTANT

Which statement is false for specific heat of water?