Physics
Heat
Easy
Question
Two identical long, solid cylinders are used to conduct heat from temp T1 to temp T2. Originally the cylinders are connected in series and the rate of heat transfer is H. If the cylinders are connected in parallel then the rate of heat transfer would be:
- H/4
- 2H
- 4H
- 8H
The correct answer is: 4H
Initially effective resistance 2R. In parallel effective R/2 resistance I t has reduced by a factor of 1/4 so0
rate of heat transfer would be increased by a factor of 4, keeping other parameters same.
Related Questions to study
Physics
Three rods made of the same material and having the same cross section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at 0°C and 90°C respectively. The temperature of the junction of the three rods will be
Three rods made of the same material and having the same cross section have been joined as shown in the figure. Each rod is of the same length. The left and right ends are kept at 0°C and 90°C respectively. The temperature of the junction of the three rods will be
PhysicsHeat
Physics
If l is the length, A is the area of cross-section and K the thermal conductivity, then the thermal resistance of the block is given by
If l is the length, A is the area of cross-section and K the thermal conductivity, then the thermal resistance of the block is given by
PhysicsHeat
Physics
The ratio of the densities of the two bodies is 3:4 and the ratio of specific heats is 43. Find the ratio of their thermal capacities for unit volume?
The ratio of the densities of the two bodies is 3:4 and the ratio of specific heats is 43. Find the ratio of their thermal capacities for unit volume?
PhysicsHeat
Physics
Two bars of thermal conductivities K and 3K and lengths 1 cm and.2 cm respectively have equal cross-sectional area, they are joined lengths wise as shown in the figure.
If the temperature at the ends of this composite bar is 0°C and Kll respectively (see figure), then the temperature 
of the interface is
Two bars of thermal conductivities K and 3K and lengths 1 cm and.2 cm respectively have equal cross-sectional area, they are joined lengths wise as shown in the figure.
If the temperature at the ends of this composite bar is 0°C and Kll respectively (see figure), then the temperature of the interface is
PhysicsHeat
Physics
Calculate the amount of heat (in calories) required to convert 5 gm of ice at 0°C to steam at 100°C
Calculate the amount of heat (in calories) required to convert 5 gm of ice at 0°C to steam at 100°C
PhysicsHeat
Physics
One kilogram of ice at 0o C is mixed with one kilogram of water at 80oC. The final temperature of the mixture is (Take specific heat of water=4200Jkg-1K-1 , Latent heat of ice=336KJ/kg-1)
One kilogram of ice at 0o C is mixed with one kilogram of water at 80oC. The final temperature of the mixture is (Take specific heat of water=4200Jkg-1K-1 , Latent heat of ice=336KJ/kg-1)
PhysicsHeat
Physics
The root mean square speed of hydrogen molecules at a certain temperature is 300m/s. If the temperature is doubled and hydrogen gas dissociates into atomic hydrogen, the rms speed will become:
The root mean square speed of hydrogen molecules at a certain temperature is 300m/s. If the temperature is doubled and hydrogen gas dissociates into atomic hydrogen, the rms speed will become:
PhysicsHeat
Physics
The temperature of an ideal gas is increased from 120K to 480K. If at 120K, the root mean square speed of the gas molecules is ‘v’, then at 480K it will be
The temperature of an ideal gas is increased from 120K to 480K. If at 120K, the root mean square speed of the gas molecules is ‘v’, then at 480K it will be
PhysicsHeat
Physics
At room temperature (270C) the ‘rms’ speed of the molecules of a certain diatomic gas is found to be 1920 ms-1. The gas is
At room temperature (270C) the ‘rms’ speed of the molecules of a certain diatomic gas is found to be 1920 ms-1. The gas is
PhysicsHeat
Physics
The mass of an oxygen molecule is about 16 times that of a hydrogen molecule. At room temperature the ‘rms’ speed of oxygen molecules is v. The ‘rms’ speed of the hydrogen molecules at the same temperature will be
The mass of an oxygen molecule is about 16 times that of a hydrogen molecule. At room temperature the ‘rms’ speed of oxygen molecules is v. The ‘rms’ speed of the hydrogen molecules at the same temperature will be
PhysicsHeat
Physics
At what temperature does the average translational kinetic energy of a molecule in a gas become equal to kinetic energy of an electron accelerated from rest through a potential difference of 1 volt ?(k=1.38x10-23J/k)
At what temperature does the average translational kinetic energy of a molecule in a gas become equal to kinetic energy of an electron accelerated from rest through a potential difference of 1 volt ?(k=1.38x10-23J/k)
PhysicsHeat
Physics
At what temperature the mean kinetic energy of hydrogen molecules increases to such that they will escape out of the gravitational field of earth for ever?
At what temperature the mean kinetic energy of hydrogen molecules increases to such that they will escape out of the gravitational field of earth for ever?
PhysicsHeat
Physics
The root mean square velocity of gas molecules at 00C will be if at N.T.P. its density is 1.43 Kg/ m3
The root mean square velocity of gas molecules at 00C will be if at N.T.P. its density is 1.43 Kg/ m3
PhysicsHeat
Physics
In the two vessels of same volume, atomic hydrogen and helium at pressure 1 atm and 2 atm are filled. If temperature of both the sample is same then average speed of hydrogen atoms < CH > will be related to that of helium < CHe > as
In the two vessels of same volume, atomic hydrogen and helium at pressure 1 atm and 2 atm are filled. If temperature of both the sample is same then average speed of hydrogen atoms < CH > will be related to that of helium < CHe > as
PhysicsHeat
Physics
The respective speeds of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/sec. The most probable speed in km/sec will be
The respective speeds of five molecules are 2, 1.5, 1.6, 1.6 and 1.2 km/sec. The most probable speed in km/sec will be
PhysicsHeat
