What is heat transfer?
Which of the following is a method of heat transfer?
Heat transfer takes place according to which of the following law?
Which of the following is the rate of heat transfer unit?
Which of the following is an example of steady-state heat transfer?
Which way is heat transfer believed to take place in a long, hollow cylinder that is kept at consistent but varied temperatures on its inner and outer surfaces?
Which of the following is correct regarding one dimensional heat transfer?
A person prefers to sit by a fire during the cold winter months. Which of the following heat transfer types gives him with the most heat?
On which of the following, convective heat transfer coefficient doesn't depend on?
In liquids and gases, heat transmission is primarily caused by
For conduction heat transfer, the heat energy propagation will be minimal for __________
A 25 mm diameter egg roll (k = 1 W/m degree) is roasted with the help of microwave heating. For good quality roasting, it is desired that temperature at the center of roll is maintained at 100 degree Celsius when the surrounding temperature is 25 degree Celsius. What should be the heating capacity in W/m 3 of the microwave if the heat transfer coefficient on the surface of egg roll is 20 W/m2 degree?
The appropriate rate equation for convective heat transfer between a surface and adjacent fluid is prescribed by which law?
A wire of radius 3 mm and 1.25 m length is to be maintained at 60 degree Celsius by insulating it by a material of thermal conductivity 0.175 W/m K. The temperature of surrounding is 20 degree Celsius with heat transfer coefficient 8.5 W/ m2 K. Find percentage increase in heat loss due to insulation?
Why fins are provided on a heat transfer surface?
A heating unit is made in the form of a vertical tube of 50 mm outside diameter and 1.2 m height. The tube is fitted with 20 steel fins of rectangular section with height 40 mm and thickness 2.5 mm. The temperature at the base of fin is 75 degree Celsius, the surrounding air temperature is 20 degree Celsius and the heat transfer coefficient between the fin as well as the tube surface and the surrounding air is 9.5 W/m2 K. If thermal conductivity of the fin material is 55 W/m K, find the amount of heat transferred from the tube without fin
Consider the following statements pertaining to heat transfer through fins
In which of the following cases provision of fins on a given heat transfer surface will be more effective?
What are the relevant boundary conditions in case of heat transfer from a bar connected to two heat sources at different temperatures?
Radiation heat transfer is characterized by
A thin metal plate of 4 cm diameter is suspended in atmospheric air whose temperature is 290 K. This plate attains a temperature of 295 K when one of its faces receives radiant energy from a heat source at the rate of 2 W. If heat transfer coefficient on both surfaces of the plate is stated to be 87.5 W/m 2 K, workout the reflectivity of the plate.
Which of the following is the unit of coefficient of radiant heat transfer?
The radiant heat transfer from a plate of 2.5 cm2 area at 1250 K to a very cold enclosure is 5.0 W. Determine the emissivity of the plate at this temperature
The calculation of heat transmission by convection is based on the determination of a Nusselt number or convective film coefficient. To that goal, which of the following strategies have been proposed
The non-dimensional parameter known as Stanton number is used in which of the following heat transfer?
The convective heat transfer coefficient in the laminar flow over a flat plate __________
Maximum heat transfer rate in a modern boiler is about
In spite of the large heat transfer coefficient in boiling liquids, fins are used advantageously when the entire surface is exposed to
The condensate film runs down a vertical flat surface where saturated steam is allowed to condense. Condensation’s local coefficient of heat transfer
A steam condenser is transferring 250 k W of thermal energy at a condensing temperature of 65 degree Celsius. The cooling water enters the condenser at 20 degree Celsius with a flow rate of 7500 kg/hr. If overall heat transfer coefficient for the condenser surface is 1250 W/m2 K, what surface area is required to handle this load?