The amount of heat flow through a body by conduction is

Heat transfer in liquid and gases take place by

Two balls of same material and finish have their diameters in the ratio of 2 : 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of

The upper surface of a weir over which water flows is known as

The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as

Which of the following is expected to have highest thermal conductivity

The time constant of a thermocouple is

When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by

In the figure given below, curve A will be applicable when thermal conductivity of the material

Heat is transferred from an insulated pipe to the surrounding still air by ________ .

Metals are good heat conductors because________ .

Highest thermal conductivity is of ________ .    

Highest thermal diffusivityis of ________ .

Film coefficient is the ratio of ________ .

In regenerator type heat exchanger, heat transfer takes place by

On a summer day,a scooter rider feels more comfortable while on the move than while at a stop lightbecause________.

In radiative heat transfer, a gray surface is one

The figure given below shows the variation of temperature across the thickness of materials with different thermal conductivities under steady states. CurveCwill be applicable when thermal conductivity of the material.

The parameter(s) responsible for loss of heat from a hot pipe surface in a room without fans would include________.

Inspite of large heat transfer coefficients in boiling liquids, fins are used advantageously when the entire surface is exposed to________ .

Which of the following would lead to a reduction in thermal resistance?

Provision of fins on a given heat transfer surface will be more if there are________ .

The total emissivity power is defined as the total amount of radiation emitted by a black body per unit.

With an increase in the thickness of insulation around a circular pipe, heat loss to surroundings due to________ .

Thermal diffusivity is________ .

Heat transfer by radiation mainly depends upon ________ .

The rate of heat transfer across any plane normal to the x-direction is proportional to the wall area and the temperature gradient in the x-direction. This statement is also referred to as _______.

The ratio of the energy absorbed by the body to total energy falling on it is called ________ .

Automobile radiator is a heat exchanger of ________ type.

Heat exchangers are used in

(a) Condensers and boilers in steam plants

(b) Radiators

(c) Intercoolers and preheaters

(d) Condensers and evaporators in refrigerators and air conditioners

Critical radius of a hollow cylinder is defined as ________ .

Minimum thermal diffusivity is of ________ .

Liquid metal having highest thermal conductivity is of ________ .

With increase in temperature, thermal conductivity of air ________ .

If thermal conductivity of a material of wall varies as k = k₀ (1+at), then the temperature at the centre of the wall as compared to that in case of constant thermal conductivity, will be _______.

The process of heat transfer from a hot body to a cold body in a straight line, without affecting the interveningmedium, is known as ________.

Heat is transferred from an electric bulb by

The process of heat transfer from one particle of the body to another without the actual motion of the particle is known as ________.

Critical thickness of insulation for spheres is given by

Two insulating materials of thermal conductivity k and 2k are available for lagging a pipe carrying a hot fluid. If the radial thickness of each material is the same ________ .

Boundary layer is defined as________ .

In regarding nucleate boiling ________ .

The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to , where n is ________ .

In a shell and tube heat exchanger, baffles are provided on the shell side to ________ .

 is known as

Which of the following is NOT a projectile motion?

“The rate of change of momentum is equal to the applied force and it takes place in the direction of the force” is a statement of :

The rate of change of linear momentum is equals to ________ .

If a light and a heavy body have equal kinetic energy of translation, then

Which of the following have same units :

A. Momentum and impulse

B. Stress and pressure

C. Work and kinetic energy