A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time

Heat Transfer
A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time

t = 800 s

t = 400 s

t = 356 s

t = 283 s

t = 800 s

t = 400 s

t = 356 s

t = 283 s

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
Steam traps are provided in steam carrying pipelines to

remove condensate and inert gases

release excess steam pressure by bleeding steam.

condense steam

none of the listed here

remove condensate and inert gases

release excess steam pressure by bleeding steam.

condense steam

none of the listed here

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case,

The cooling rate will be the same for the two spheres and hence the two spheres will have equal temperatures at any instant

Both the spheres will emit equal amount of radiation per unit time in the beginning

Both will absorb equal amount of radiation from the surrounding in the beginning

Both B & C

The cooling rate will be the same for the two spheres and hence the two spheres will have equal temperatures at any instant

Both the spheres will emit equal amount of radiation per unit time in the beginning

Both will absorb equal amount of radiation from the surrounding in the beginning

Both B & C

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be

Initially decreases and remains constant thereafter

More than 45°C

Equal to 45°C

Less than 45°C

Initially decreases and remains constant thereafter

More than 45°C

Equal to 45°C

Less than 45°C

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is

2.36

Dependent on NRe only

4.36

120.36

2.36

Dependent on NRe only

4.36

120.36

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
For a given ambient air temperature with increase in the thickness of insulation of a hot cylinderical pipe, the rate of heat loss from the surface would

Increase

First increase and then decrease

First decrease and then increase

Decrease

Increase

First increase and then decrease

First decrease and then increase

Decrease

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer

Heat Transfer Steam traps are provided in steam carrying pipelines to

Heat Transfer A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case,

Heat Transfer In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be

Heat Transfer The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is

Heat Transfer For a given ambient air temperature with increase in the thickness of insulation of a hot cylinderical pipe, the rate of heat loss from the surface would

Heat Transfer
Steam traps are provided in steam carrying pipelines to

Heat Transfer
A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case,

Heat Transfer
In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be

Heat Transfer
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is

Heat Transfer
For a given ambient air temperature with increase in the thickness of insulation of a hot cylinderical pipe, the rate of heat loss from the surface would