Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
21. Which of the following statements state that no process is possible whose sole result is the transfer of heat from a colder object to a hotter object?
[A] Kevin-Plank statement
[B] Einstein’s statement
[C] Clausius statement
[D] None of the above
Show Answer
Correct Answer: C [Clausius statement]
Notes:
Clausius statement: No process is possible whose sole result is the transfer of heat from a colder object to a hotter object.
22. Which of the following regions of electromagnetic spectrum is called as light?
[A] 100 nm – 1000 nm
[B] 400 nm – 10000 nm
[C] 100 nm – 20000 nm
[D] 400 nm – 750 nm
Show Answer
Correct Answer: D [400 nm – 750 nm]
Notes:
Electromagnetic radiation belonging to region of the electromagnetic spectrum having wavelength of about 400 nm to 750 nm is called light.
23. Which of the following cells is the basis of Non-rechargeable batteries?
[A] Galvanic cells
[B] Electrolytic cells
[C] Both a and b
[D] None of the above
Show Answer
Correct Answer: A [Galvanic cells]
Notes:
Non-rechargeable batteries are examples of Galvanic cells.
24. What kind of cell is the mobile phone battery when it is being charged?
[A] Galvanic cell
[B] Fuel cell
[C] Electrolytic cell
[D] None of the above
Show Answer
Correct Answer: C [Electrolytic cell]
Notes:
While the battery is being used in the device it is a galvanic cell function (using the redox energy to produce electricity). While the battery is charging it is an electrolytic cell function (using outside electricity to reverse the completed redox reaction).
25. What is the SI unit of magnetic flux?
[A] teslas
[B] maxwell
[C] weber
[D] Newton
Show Answer
Correct Answer: C [weber]
Notes:
The SI unit of magnetic flux is the weber (Wb) and the CGS unit is the maxwell.
26. Which of the following is a suitable material for making a permanent magnet?
[A] alnico
[B] cobalt steel
[C] ticonal
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Soft iron, alnico, cobalt steel and ticonal are some of the suitable materials for permanent magnets.
27. Which of the following statements related to the unit curie (Ci) is correct?
[A] 1 Ci = 3.7 × 107
[B] 1 Ci = 2.7 × 109
[C] 1 Ci = 2.7 × 107
[D] 1 Ci = 3.7 × 1010
Show Answer
Correct Answer: D [1 Ci = 3.7 × 1010]
Notes:
There is also another unit named “curie” that is widely used and is related to the SI unit as: 1 curie = 1 Ci = 3.7 × 1010 decays per second = 3.7 × 1010 Bq
28. At what temperature (in Fahrenheit), pure water freezes?
[A] 32
[B] 0
[C] 48
[D] 37
Show Answer
Correct Answer: A [32]
Notes:
On the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit (°F) and the boiling point is 212 °F (at standard atmospheric pressure). This puts the boiling and freezing points of water 180 degrees apart.
29. What is the reason for formation of Mirage in desert?
[A] Refraction of light
[B] Reflection of light
[C] Total internal reflection of light
[D] Both Refraction and Total internal reflection of light
Show Answer
Correct Answer: D [Both Refraction and Total internal reflection of light]
Notes:
Mirage is formed due to both Refraction and Total internal reflection of light. A mirage is a naturally occurring optical phenomenon in which light rays bend to produce a displaced image of distant objects or the sky.
30. Speed of light is maximum in which of the following mediums?
[A] gases
[B] solids
[C] liquids
[D] vacuum
Show Answer
Correct Answer: D [vacuum]
Notes:
The speed of light in a vacuum is 186,282 miles per second. Nothing can travel faster than the speed of light in a vacuum. A vacuum is a region with no matter in it.
