1113 RAS Prelims practice MCQs on science and technology are on this page, in 6 chapters. They cover the basics of everyday science, computers and information technology, defence and space technology in India, genetics, biotechnology and nanotechnology, science and technology policies and government programmes, and recent advances with Indian contributors and indigenisation. Each question has an answer and an explanation.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 51–60 of 1113 questions
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RAS PrelimsScience and Technology · Basics of Everyday Science
Q51. Consider the following statements about light: I. Light travels faster in a vacuum than in glass. II. Refraction occurs when light passes from one medium to another with a different optical density. III. The angle of incidence is always less than the angle of reflection. Which of the above statement(s) is/are correct?
Explanation
Light travels at its maximum speed in a vacuum and slows down when entering denser media like glass. Refraction is the bending of light as it crosses boundaries between materials with different optical densities. Regarding reflection, the law states that the angle of incidence is always equal to the angle of reflection, not less than it, making the third statement factually incorrect.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q52. The splitting of white light into its component colors upon passing through a prism is called:
Explanation
Dispersion is the process where white light separates into its constituent colors--red, orange, yellow, green, blue, indigo, and violet--when passing through a medium like a glass prism. This happens because different wavelengths of light travel at different speeds and refract at slightly different angles. This fundamental optical phenomenon is responsible for the natural formation of rainbows in the sky after rain.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q53. The formation of a mirage in deserts is an optical illusion primarily due to:
Explanation
A mirage is an optical illusion caused by the refraction and total internal reflection of light in the atmosphere. On hot days, layers of air near the ground become much warmer and less dense than the air above. Light from the sky travels through these layers and bends upward, creating a displaced image that often looks like a pool of shimmering water.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q54. A person suffering from myopia (near-sightedness) is typically prescribed a lens of which type?
Explanation
Myopia, or near-sightedness, occurs when the eye’s lens is too curved or the eyeball is too long, causing images to focus in front of the retina rather than on it. To correct this, a concave or diverging lens is used. This lens spreads the incoming light rays outward before they reach the eye, allowing the image to focus correctly on the retinal surface.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q55. The blue color of the clear sky is mainly due to the:
Explanation
The blue appearance of the sky is a result of Rayleigh scattering. When sunlight enters the Earth’s atmosphere, it interacts with gas molecules and small particles. Shorter wavelengths of light, specifically blue and violet, are scattered in all directions more efficiently than longer wavelengths. Although violet scatters more, our eyes are more sensitive to blue, making the sky appear blue.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q56. What type of mirror is commonly used by dentists to examine teeth?
Explanation
Dentists use concave mirrors to examine teeth because they can produce a magnified, upright, and clear virtual image of an object when it is placed close to the mirror’s surface. This magnification allows the dentist to see fine details and small cavities that might be missed with the naked eye, improving diagnostic accuracy during dental procedures.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q57. Match the optical phenomena in List I with their corresponding examples in List II.
Optical Phenomenon
Example/Application
A. Total Internal Reflection
i. Rainbow formation
B. Scattering of light
ii. Twinkling of stars
C. Dispersion of light
iii. Optical fibers
D. Refraction of light
iv. Red color of sun at sunrise
Explanation
Total internal reflection is the principle behind optical fibers. Scattering of light by the atmosphere causes the sun to appear red at sunrise. Dispersion of sunlight by water droplets creates rainbows. The twinkling of stars is caused by atmospheric refraction as light passes through varying air densities. These phenomena illustrate how light interacts with different media to produce distinct visual effects.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q58. The power of a lens is measured in:
Explanation
The power of a lens is a measure of its ability to converge or diverge light rays and is mathematically defined as the reciprocal of its focal length in meters. The standard unit for measuring this power is the diopter. A lens with a short focal length has a higher power in diopters, indicating a stronger bending effect on the light passing through it.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q59. When light passes from a denser medium to a rarer medium, it bends:
Explanation
When light travels from an optically denser medium, like water, into a rarer medium, like air, its speed increases. This change in speed causes the light ray to bend away from the normal line at the boundary. If the angle of incidence exceeds a certain critical value, the light will undergo total internal reflection and remain within the denser medium entirely.
RAS PrelimsScience and Technology · Basics of Everyday Science
Q60. The speed of light in a vacuum is exactly defined as:
Explanation
The speed of light in a vacuum is a fundamental physical constant. It is defined exactly as two hundred and ninety-nine million, seven hundred and ninety-two thousand, four hundred and fifty-eight meters per second. This value is used to define the meter in the International System of Units. While often rounded for simplicity, the exact figure is fixed and unchanging in physics.
Answer key for these questions
Q
Correct answer
51
(a) I and II only
52
(d) Dispersion
53
(c) Total internal reflection
54
(b) Concave lens
55
(d) Scattering of shorter solar wavelengths by air molecules
56
(a) Concave mirror
57
(a) A-iii, B-iv, C-i, D-ii
58
(a) Diopters
59
(b) Away from the normal
60
(b) 299,792,458 m/s
Key facts from Science and Technology
The RPSC paper is General Knowledge and General Science, so science questions come with a strong dose of applied and recent topics.
Everyday science questions test the laws and terms of physics, chemistry and biology through examples.
Defence and space questions pair a missile, satellite or mission with its year and organisation.
Policy questions ask for the year, the body and the aim of schemes like STIP, the National Quantum Mission and BioE3.
Health, environment and agriculture are on a separate page, with their own chapters.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Science and Technology?
This page has 1113 practice MCQs on Science and Technology. Each has the correct answer, and most have an explanation.
Which chapters does the science and technology set cover?
Six chapters: basics of everyday science; computers, information and communication technology; defence and space technology in India; genetics, biotechnology and nanotechnology; science and technology policies and government programmes; and recent advances, Indian contributors and indigenisation.
Is science and technology part of the RAS Prelims syllabus?
Yes. The RPSC paper is called General Knowledge and General Science, and its syllabus lists science and technology topics along with environment, health, agriculture and government programmes, so questions can come from any of these areas.
How should I prepare science for RAS Prelims?
Revise the concepts by examples, then learn the missions, schemes and scientists with their year and organisation. Attempt each chapter, read the explanations and keep a list of the facts you missed.
