0

114226

Description: Thermodynamics (E)
Number of Questions: 15
Created by:
Tags: Thermodynamics (E) General Science General Awareness General Science & Scientific Terminology Thermodynamics Physics Chemistry
Attempted 0/15 Correct 0 Score 0

Human body is an example of

  1. isolated system

  2. closed system

  3. open system

  4. adiabatic system


Correct Option: C
Explanation:

This system involves the exchange of both matter and energy with the surroundings. Since human body exchanges both matter and energy with the surroundings, it is an open system.

Which of the following strokes is the difference between a four stroke engine and six stroke engine?

  1. Suction stroke

  2. Compression stroke

  3. Power stroke

  4. Exhaust stroke


Correct Option: C
Explanation:

The basic difference between a four stroke engine and a six stroke engine is in power stroke. In a six stroke engine, there are two power strokes in the six stroke cycle.

In thermos flask, tea remains hot for very longtime because the flask shows _________.

  1. isothermal process

  2. adiabatic process

  3. isobaric process

  4. isochoric process


Correct Option: B
Explanation:

The process that occurs without gain or loss of heat is called adiabatic process. The inner container is covered with an outer cover with no air in between. So, there is no conduction of heat from outside to the inner layer.

The reason to add coolant in a motor engine is to

  1. increase the acceleration

  2. reduce the volume of harmful exhaustible gases

  3. to lower the temperature of the engine

  4. to increase the lubrication of piston of the engine


Correct Option: C
Explanation:

Coolant is a fluid, which flows through the engine to prevent its overheating. It is also called ‘anti-freeze’, which keeps the water that cools the engine from freezing.

Which one of the following is not an intensive property in thermodynamics?

  1. Pressure

  2. Density

  3. Volume

  4. Temperature


Correct Option: C
Explanation:

Intensive property is the property which depend only upon the nature of substance and are independent of the amount of the substance present in the sytem. Pressure, density, surface tension and temperature are intensive property but volume is not an intensive property.

Why is salt is used to melt ice?

  1. To lower the freezing point of water.

  2. To increase the melting point of water.

  3. Both (1) and (2)

  4. To produce the heat by decomposition of salt molecules.


Correct Option: A
Explanation:

Salt acts as anti-freeze. Water becomes ice at a temperature of 32 degrees Fahrenheit (0 degrees Celsius) and adding salt to water lowers the freezing point, thus preventing the formation of ice.

Which of the following is not involved in the working of an air conditioner?

  1. Evaporator

  2. Condensor

  3. Compressor

  4. Radiator


Correct Option: D
Explanation:

An air conditioner is composed of three main parts: compressor, condenser and evaporator. Radiator is a component of motor engine.

Which of the following principles is/are involved in adding the layer of mud and straw on the roof of a house?

  1. Heat convention

  2. Heat radiation

  3. Heat conduction

  4. Both (1) and (3)


Correct Option: C
Explanation:

A layer of mud and straw is laid over the roof of the house in between the concrete and brick tiles. This layer does not conduct heat due to sun rays into the room of the house through the roof and helps to keep the room cool in summer.

Which of the following gases is present in an air conditioner?

  1. Neon

  2. Freon

  3. Methane

  4. Helium


Correct Option: B
Explanation:

Freon is a chlorofluorocarbon (CFC-113). In addition to being used in air conditioning systems, it is also used as refrigerant in refrigerators and freezers and also in firefighting systems, and as an aerosol propellant.

Which of the following gets condensed while heating?

  1. Plastic

  2. Steel

  3. Brass

  4. Glass


Correct Option: A
Explanation:

Among all the options, plastic gets condensed while heating and the others expand.

In a cold day the smoke spreads in a flat layer above the icy cold river rather than rising and dissipating into the atmosphere. It is due to

  1. the decrease in temperature

  2. the increase in temperature

  3. the inversion of temperature

  4. rapid and sudden fall in tempreture over the river.


Correct Option: C
Explanation:

The atmosphere above a icy cold river depicts inversion of temperature with warm air at the top and cold air near the surface of the river. Warm moist air does rise above a river but expands and cools down and as condensation occurs the air becomes denser and it sinks to lower levels with warm air at the top. If the rising smoke is denser than the upper warm air, it is not able to rise further but spreads out in flat layers.

Evaporation of water from a pond is an example of

  1. isolated system

  2. open system

  3. closed system

  4. homogeneous system


Correct Option: B
Explanation:

A system which can exchange matter as well as energy with the surroundings is called an open system. For example, water in a pond as it can gain or lose matter and energy with the surroundings.

Which of the following heat transfer mechanisms does not require a medium?

  1. Conduction

  2. Convection

  3. Vibration

  4. Radiation


Correct Option: D
Explanation:

Radiation heat transfer is concerned with the exchange of thermal radiation energy between two or more bodies. No medium is required for heat transfer by radiation; the radiation can travel through vacuum. For example, the heat is transferred from the sun to the earth by this method.

Two thin blankets are warmer than a single blanket of same thickness as the two because

  1. the thermal conductivity is less than that of one

  2. some air sheet is enclosed in between them preventing heat flow

  3. the weight of two blankets is more than the one

  4. none of these


Correct Option: B
Explanation:

 Two thin blankets are warmer than a single blanket of same thickness as the two because some air sheet is enclosed in between them preventing heat flow .

The apparatus used for measuring heat change is called

  1. thermometer

  2. voltameter

  3. calorimeter

  4. voltmeter


Correct Option: C
Explanation:

A calorimeter is an object used for calorimetry or the process of measuring the heat of chemical reactions or physical changes.

- Hide questions