General Science - 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. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
41. 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.
42. Which of the following eye-defects is also known as far -sightedness?
[A] Myopia
[B] Hyper-metropia
[C] Cataract
[D] None
Show Answer
Correct Answer: B [Hyper-metropia]
Notes:
Hypermetropia is also known as far -sightedness. A person with hypermetropia can see distant objects clearly but cannot see nearby objects distinctly.
43. 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.
44. What is the property of a conductor to resist the flow of charges known as?
[A] Conductance
[B] Conductivity
[C] Resistance
[D] Electric Potential
Show Answer
Correct Answer: C [Resistance ]
Notes:
Resistance is the property of a conductor to resist the flow of charges. Resistance is constant for the given metal at a given temperature.
45. What is the equivalent internal resistance of a series combination of n cells?
[A] the arithmetic mean of their internal resistance
[B] the product of their individual internal resistance
[C] the sum of their individual internal resistance
[D] the sum of the reciprocal of their individual internal resistance
Show Answer
Correct Answer: C [the sum of their individual internal resistance]
Notes:
The equivalent internal resistance of a series combination of n cells is just the sum of their internal resistances.
46. Which of the following phenomenon is the basis of an electric generator?
[A] Electromagnetic Induction
[B] Ferroelectric effect
[C] Telluric currents
[D] Electroluminescence
Show Answer
Correct Answer: A [Electromagnetic Induction]
Notes:
In an electric generator, mechanical energy is used to rotate a conductor in a magnetic field to produce electricity.
47. What is the susceptibility of a diamagnetic material?
[A] positive and small
[B] positive and large
[C] negative
[D] None
Show Answer
Correct Answer: C [negative]
Notes:
In terms of the susceptibility χ , a material is diamagnetic if χ is negative, para- if χ is positive and= small, and ferro- if χ is large and positive
48. 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
49. What is the output of an OR gate when both the inputs are 1?
[A] 0
[B] 1
[C] Either 0 or 1
[D] None
Show Answer
Correct Answer: B [1]
Notes:
The OR gate is a digital logic gate that gives a HIGH output if one or both the inputs to the gate are HIGH.
50. What do we call an undoped semiconductor?
[A] Intrinsic semiconductor
[B] Extrinsic semiconductor
[C] p-type semiconductor
[D] None of the above
Show Answer
Correct Answer: A [Intrinsic semiconductor]
Notes:
An intrinsic semiconductor is an undoped semiconductor. This means that holes in the valence band are vacancies created by electrons that have been thermally excited to the conduction band.
