InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
mean free path of a gas molecule increases with decrease inA. temperature and molecular diameter of the gas moleculeB. molecular diameter and pressure of the gas of the gas moleculeC. density and temperature of the gas moleculeD. volume of the gas |
| Answer» Correct Answer - B | |
| 2. |
Mean free path of a gas molecule increases with decreases inA. temperature of the gas moleculeB. diameter of the gas moleculeC. density of the gas moleculeD. diameter and density of the gas molecule |
| Answer» Correct Answer - D | |
| 3. |
Mean free path of a gas molecule increases with increase inA. temperature of the gas molculeB. diameter of the gas moleculeC. density of the gas moleculeD. temperature diameter and density of the gas molecule |
| Answer» Correct Answer - A | |
| 4. |
Mean free path of a gas molecule in a container depends uponA. temperature of the gas molecule onlyB. diameter of the gas molecule onlyC. density of the gas molecule onlyD. temperature diameter and density of the gas molecule |
| Answer» Correct Answer - D | |
| 5. |
In a gas equation, `PV = RT, V` refers to the volume ofA. any amount of gasB. one gram mole of gasC. one gram of gasD. one litre of a gas |
| Answer» Correct Answer - B | |
| 6. |
A piece of charcoal and a piece of shining steel of the same surface area are kept for a long time in an open lawn in bright sun.A. the steel will absorb more heat than the charcoalB. the temperature of the steel will be lower than that of the charcoalC. if both are picked up by bare hands, the steel will be felt hotter than the charcoalD. if both are picked up by bare hands, the charcoal will be felt hotter than steel |
| Answer» Correct Answer - C | |
| 7. |
The false statement in the following isA. radiations are electromagnetic wavesB. radiations can pass through vacuumC. radiations travel with the velocity of lightD. none of the above |
| Answer» Correct Answer - D | |
| 8. |
In a thermos flask, attempt is made to reduce losses of heat byA. conduction onlyB. conduction and convectionC. convection onlyD. conduction, convection and radiation |
| Answer» Correct Answer - D | |
| 9. |
In winter, the temperature inside the wall of a room as compared to the temperature of air is the room isA. lowerB. higherC. sameD. may be lower or higher depending on atmospheric pressure |
| Answer» Correct Answer - B | |
| 10. |
The door of a running refrigerator inside a room is left open. The correct statement out of the following ones isA. cooledB. warmedC. no effectD. first heated then cooled |
| Answer» Correct Answer - B | |
| 11. |
Heat radiations cannot exhibit the following phenomenon. That isA. interferenceB. diffractionC. polarisationD. beats |
| Answer» Correct Answer - D | |
| 12. |
The light from th sun is found to have a maximum intensity near the wavelength of `470nm`. Assuming that the surface of the sun emits as a blackbody, calculate the temperature of the surface of the sun.A. 5800 KB. 6050 KC. 6166 KD. 6500 K |
| Answer» Correct Answer - C | |
| 13. |
Who explained the Fraunhoffer line in the spectrum of solar radiations?A. WeinB. StefanC. KirchhoffD. Fraunhoffer |
| Answer» Correct Answer - C | |
| 14. |
Internal latent heat is defined asA. amount of heat needed to do work against external pressureB. amount of heat needed to do to work against intermolecular forceC. amount of heat needed to increase the K.E. of the moleculesD. heat needed to change the state of a substance |
| Answer» Correct Answer - B | |
| 15. |
The substance which allows heat radiations to pass through it isA. ironB. water vapourC. woodD. dry air |
| Answer» Correct Answer - D | |
| 16. |
SI unit of heat isA. calorieB. kilo calorieC. jouleD. ergs |
| Answer» Correct Answer - C | |
| 17. |
For each of the equation four choices have been provided .select the correct alternative SI unit of specific heat capacity is ______.A. kcal/kg KB. J/ mole KC. J/kg KD. kcal/kmol K |
| Answer» Correct Answer - C | |
| 18. |
The mean transitional kinetic energy of a perfect gas molecule at absolute temperature `T` is (`k` is the Boltzmann constant)A. 1/2 KTB. 1/2 RTC. 3/2 KTD. 3/2 RT |
| Answer» Correct Answer - D | |
| 19. |
The mean transitional kinetic energy of a perfect gas molecule at absolute temperature `T` is (`k` is the Boltzmann constant)A. 1/2 KTB. 3/2 KTC. KTD. 2 KT |
| Answer» Correct Answer - B | |
| 20. |
If a gas expands under isothermal conduction, then what happen to rms velocity will be?A. increasesB. decreasesC. remains constantD. can not be predicted |
| Answer» Correct Answer - C | |
| 21. |
A medium is not required for transfer of thermal energy from one body to another body isA. conductionB. convectionC. radiationD. all of these |
| Answer» Correct Answer - C | |
| 22. |
According to the kinetic theory of gasses pressure exerted by perfect gas molecule on the wall of a container is equal to momentum transferred to the wall per unit areaA. by only one moleculeB. per second by only moleculesC. per second by one-third moleculesD. by one-third molecules |
| Answer» Correct Answer - C | |
| 23. |
It is hotter at some distance over the fire than in front of it becauseA. heat is radiated upwards onlyB. convection heat takes downwards onlyC. air conducts heat upwards onlyD. convection takes more heat upwards |
| Answer» Correct Answer - D | |
| 24. |
The slowest mode of transfer of heat isA. conductionB. convectionC. radiationD. all the above |
| Answer» Correct Answer - A | |
| 25. |
In conduction mode, heat an be transferred from a point ofhigher temperature of the point of lower temperatureA. with the actual migration of the particles of mediumB. without actual migration of the particles of mediumC. in the form of elecromagnetic radiationD. in the form of corpuscles |
| Answer» Correct Answer - B | |
| 26. |
In radiation mode, heat energy can be transfferredA. in presence of material mediumB. without any material mediumC. in presence of any material medium or without any material mediumD. none of these |
| Answer» Correct Answer - C | |
| 27. |
The bulbs of two identical thermometers are coated one with lamp black an the other with silver thin film coated. When exposed in sun light for shorter time then the reading of the thermometer with lamp black coating will beA. more than that with silver coatingB. less than that with silver coatingC. same of that with silver coatingD. nothing can be predicted |
| Answer» Correct Answer - A | |
| 28. |
Heat radiation have wavelengths in the region ofA. visible lightB. ultravioletC. radiowaveD. infrared |
| Answer» Correct Answer - D | |
| 29. |
By which of the following methods could a cup of hot tea loss heat when placed on metallic table in a class room .A. conductionB. convectionC. radiation and evaporationD. all |
| Answer» Correct Answer - D | |
| 30. |
In which of the following process, convection does not take place primarilyA. sea and land breezeB. boiling of waterC. warming of glass of bulb due to filamentD. heating air around a furnace |
| Answer» Correct Answer - C | |
| 31. |
The transmission of heat by molecular collision is calledA. conductionB. convectionC. radiationD. scattering |
| Answer» Correct Answer - A | |
| 32. |
A ferfectly black body is one which absorbs radiation ofA. all wavelengthsB. large wavelengthsC. small wavelengthsD. infrared wavelengths |
| Answer» Correct Answer - A | |
| 33. |
Two persons ordered tea in a restaurant and waited for a friend to arrive. The first person mixed hot tea and cold milk in the cup and wated for the fried and the second mixed hot tea and hot milk in the cup after the arrival of the friend. Milk in the cup after the arrival of the friend. If the temperature of the two cups of tea are `T_(1) and T_(2)` respectively, then.A. `T_(1) lt T_(2)`B. `T_(1)=T_(2)`C. `T_(1) gtT_(2)`D. `T_(1) ge T_(2)` |
| Answer» Correct Answer - C | |
| 34. |
A hot and a cold body are kept in vacuum separated from each other. Which of the following cause decrease in temperature of the hot bodyA. RadiationB. ConvectionC. ConductionD. Temperature remains unchanged |
| Answer» Correct Answer - A | |
| 35. |
An electric heater kept in vacuum is heated continuously by passing electric current. Its temperatureA. go on rising with timeB. stop rising after some time as it will lose heat to surroundings by conductionC. will rise for some time and there after will start fallingD. will become constant after some time due to loss of heat by radiation |
| Answer» Correct Answer - D | |
| 36. |
A polished metal plate with a rough black spot on it is heated to about `1400K` and quickly taken into dark room Then .A. The spot will appear brighter that the plateB. the spot will appear darker than the plateC. the spot and the plate will appear equally brightD. the spot and the plate will not be visible in the dark room |
| Answer» Correct Answer - A | |
| 37. |
A black hole, absorbsA. all radiationB. all radiations except X-raysC. all radiations except visible radiationsD. X-rays only |
| Answer» Correct Answer - C | |
| 38. |
A solid sphere and a hollow sphere of the same material and of equal radii are heated to the same temperatureA. both will emit equal amount fo radiation per unit time in the beginningB. both will absorb equal amount of radiation from the surrounding in the beginningC. the initial rate of cooling will not be same for the two sphereD. the two spheres will have equal temperature at any instant |
| Answer» Correct Answer - D | |
| 39. |
Emissive power of a perfectly black bodyA. absorption powerB. transmative powerC. reflective powerD. none of the above |
| Answer» Correct Answer - D | |
| 40. |
S.I unit of emissive power isA. `J//s`B. `J//m^(2)`C. `J//s" "m^(2)`D. Watt/m |
| Answer» Correct Answer - C | |
| 41. |
The ratio of spectral emissive power of a body `lamda` and temperature T is equal to a physical quantity at the wavelength and temperature. Then the physical quantity isA. emissive power of the bodyB. absorptive powe of the bodyC. reflective power of the bodyD. transmission coefficient of the body |
| Answer» Correct Answer - B | |
| 42. |
Two bodies one hot an the other cold are kept in vacuum. What will happen to the temperature of the hot body after some time?A. remain the sameB. decrease due to radiationC. increase due to radiationD. increase due to convection |
| Answer» Correct Answer - B | |
| 43. |
TEMPERATURE AND ZEROTH LAW OF THERMODYNAMICSA. zerothB. firstC. secondD. third |
| Answer» Correct Answer - A | |
| 44. |
"It is impossible to convert total heat into work" thiis is the statement of -_____ law of thermodynamics.A. zeroth lawB. first lawC. second lawD. third law |
| Answer» Correct Answer - C | |
| 45. |
There is a circularr hole in a square copper plate. If the plate is heated then the radius of the circular hole willA. increaseB. decreaseC. remains sameD. increase or decrease dependeing on size of the square plate |
| Answer» Correct Answer - A | |
| 46. |
A vessel full of hot water is kept in a room and it cools from `80^(@)C` to `75^(@)C` in `T_(1)` minutes, from `75^(@)C` to `70^(@)C` in `T_(2)` minutes and from `70^(@)C` to `65^(@)C` in `T_(3)` minutes Then .A. `t_(1)=t_(2)=t_(3)`B. `t_(1) lt t_(2)=t_(3)`C. `t_(1) lt t_(2) lt t_(3)`D. `t_(1) gt t_(2) gt t_(3)` |
| Answer» Correct Answer - C | |
| 47. |
At a certain temperature for given wavelength, the ratio of emissive power of a body to emmisve power of black body in same circumstance in known asA. relative emissivityB. emissivityC. of transmission coefficientD. coefficient of reflection |
| Answer» Correct Answer - B | |
| 48. |
In the above problem the ratio of the initial rate of fall of the temperatures is nearlyA. 2.49B. 3.11C. 1.99D. 24.9 |
| Answer» Correct Answer - A | |
| 49. |
Two bodies A and B are said to be in thermal equilibrium with each other if they have sameA. amount of heatB. specific heatC. temperatureD. thermal capacity |
| Answer» Correct Answer - C | |
| 50. |
When a body of mass M loses heat, the rate of fall of temperature is proportional toA. `M^(1//2)`B. `M^(-1//2)`C. MD. `M^(-1)` |
| Answer» Correct Answer - D | |