Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
21. What do we call the process in which no exchange of heat energy takes place between the gas and the surroundings?
[A] Adiabatic
[B] Isothermal
[C] Isochoric
[D] Isobaric
Show Answer
Correct Answer: A [Adiabatic]
Notes:
A process in which no exchange of heat energy takes place between the gas and the surroundings, is called an adiabatic process.
22. Which of the following is true about the focal length of a spherical mirror?
[A] it is equal to its radius of curvature
[B] it is equal to half its radius of curvature
[C] it is equal to twice its radius of curvature
[D] None of the above
Show Answer
Correct Answer: B [it is equal to half its radius of curvature]
Notes:
The focal length of a spherical mirror is equal to half its radius of curvature.
23. In which of the following cases a concave mirror will form a virtual and erect image?
[A] when object is placed at infinity
[B] when object is at focus
[C] when object is between pole and focus
[D] None of the above
Show Answer
Correct Answer: C [when object is between pole and focus]
Notes:
When the object is between pole and focus, a concave mirror will form a virtual and erect image.
24. What is the nature of image formed by a convex mirror when the object is placed at infinity?
[A] Real and inverted
[B] Virtual and erect
[C] Virtual and inverted
[D] Real and erect
Show Answer
Correct Answer: B [Virtual and erect]
Notes:
Virtual and erect image is formed by a convex mirror when the object is placed at infinity
25. What are the lines joining places of zero declination known as?
[A] Isoclinic
[B] Agonic
[C] Aclinic
[D] Isogonic
Show Answer
Correct Answer: B [Agonic]
Notes:
The line joining places of zero declination is known as agonic line.
26. Which of the following is correct?
[A] Soft iron is a hard ferromagnetic material
[B] Alnico is a soft ferromagnetic material
[C] At high enough temperature, a ferromagnet becomes a paramagnet
[D] All of the above
Show Answer
Correct Answer: C [At high enough temperature, a ferromagnet becomes a paramagnet]
Notes:
The ferromagnetic property depends on temperature. At high enough temperature, a ferromagnet becomes a paramagnet. Soft iron is a soft ferromagnetic material and Alnico is a hard ferromagnetic material.
27. What is the SI unit of radioactivity?
[A] Becquerel
[B] candela
[C] curie
[D] Henry
Show Answer
Correct Answer: A [Becquerel]
Notes:
The System International of units (SI system) uses the unit of Becquerel (Bq) as its unit of radioactivity. 1 Becquerel is simply equal to 1 disintegration or decay per second.
28. What are the nuclei of different atoms containing same number of neutrons known as?
[A] Isobars
[B] Isotopes
[C] Isotones
[D] Isomers
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Correct Answer: C [Isotones]
Notes:
Nuclei of different atom containing same number of neutrons are called isotones.
29. What is the minimum number of logic gates in a VLSI?
[A] 10
[B] 100
[C] 1000
[D] 10000
Show Answer
Correct Answer: C [1000]
Notes:
If the number of logic gates in a circuit is greater than 1000, we call it as VLSI – very large scale integration
30. A simple microscope consists of which of the following lenses?
[A] a short focus convex lens
[B] a short focus concave lens
[C] a long focus concave lens
[D] a long focus convex lens
Show Answer
Correct Answer: A [a short focus convex lens]
Notes:
The use of a single short focus convex lens or groups of lenses are found in simple magnification devices such as the magnifying glass, loupes, and eyepieces for telescopes and microscopes. If a convex lens is held close to a person’s eyes, they will see an image that is upright and larger than the actual object.
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