ESE Prelims 2022 Achievers Quiz 3

For a cylindrical rod with uniformly distributed heat sources, the thermal gradient dt/dr at half the radius location will be

In winter, the inside temperature of house is maintained at 22°C and outside temperature is –5°C. If wall which is separating the inside environment from outside is made up of two layer of different material having thermal conductivity 0.15 is 0.01 and thickness 20 cm & 10cm respectively. If the convection heat transfer coefficient of inside & output is & then heat flux from inside to outside will be

Consider a medium in which the heat conduction equation is given in its simplest form as

1) Heat transfer is steady

2) Heat transfer is three dimensional.  

3) There is no heat generation in the medium

4) The thermal conductivity of the medium is constant.
5) it is spherical conduction equation. 

Which of the above statement is/are correct?

The temperature distribution in a body is given by :

What is the value of  , considering there is no internal heat generation inside the slab and (thermal diffusivity) remains constant through out the time

In a jet engine, the front of engine acts as a diffuser and receives air at 900 km/h, -5^oC , 50 kPa. It brings it to 80 m/s relative to the engine before entering the compressor. If the flow area is reduced to 80% of the inlet area,the  pressure (in KPa) at the compressor inlet is _____. (Assume no heat transfer)

Match the items in list I to those in list II

List-I

A) Heat to work

B) Heat to lift weight

C) Heat to strain energy

D) Heat to electromagnetic energy

List II

1) Heat engine

2) Hot air balloon/evaporation

3) Thermal radiation

4) Bimetallic strips

A hair dryer is basically a duct of constant diameter in which a small fan pulls the air in and forces it through resistors where it is heated. If the density of air is 1 kg/ at the inlet and 0.80 at the outlet, determine the percentage increase in velocity of air at exit as it flows through the dryer.

A rigid tank when the temperature is 10˚C and the pressure is 150kPa. On a hot day, the temperature in the tank reaches 50˚C. Assume ideal gas behaviour. If a small hole is drilled in the tank and the gas escapes isentropically to the atmosphere, then the velocity(m/s) of escaping air is? (P_atm = 100kPa, C_p = 1kJ/kgK and )