Science Quiz for NDA, CDS and CAPF Exam:13 August

Q1. The speed of light will be minimum while passing through- 
(a) Glass
(b) Vacuum
(c) Water
(d) Air

Q2. The radius of curvature of the plane mirror is: 
(a) Zero
(b) One
(c) Infinity
(d) Between one and infinity

Q3. Which one of the following is the best conductor of electricity? 
(a) Mica
(b) Copper
(c) Gold
(d) Silver

Q4. Which is not used as Atomic fuel? 
(a) Uranium
(b) Thorium
(c) Plutonium
(d) Lead

Q5. The gas used in discharge tubes for optical decoration and advertising is- 
(a) Carbon dioxide
(b) Ammonia
(c) Sulphur dioxide
(d) Neon

Q6. Which one of the following pairs is not correctly matched: 
(a) Discovery of Meson                                                -   Hideki Yukawa
(b) Discovery of Positron                                               -   C.D. Anderson and U.F. Hess
(c) Theory of energy production in the sun and stars     -   H.A. Bethe
(d) Synthesis of transuranic elements                           -    Enrico Fermi transuranic elements

Q7. The maximum density of water is at 
(a) 373 Kelvin
(b) 277 Kelvin
(c) 273 Kelvin
(d) 269 Kelvin

Q8. The technique to integrate and mark the image of a three- the Dimensional object is- 
(a) Audiography
(b) Lexieography
(c) Photography
(d) Holography

Q9. Which type of electromagnetic radiation is used in the remote control of a television receiver? 
(a) Visible
(b) Ultra-violet
(c) Infra-red
(d) None of the above

Q10. Which one of the following is not correct:  
(a) Theory of evolution was propounded by Charles Darwin.
(b) The breaking apart of the he nucleus of an atom is called fusion.
(c) ‘Dry ice’ is nothing but solid carbon dioxide.
(d) The telephone was invented by Graham Bell.


S1. Ans. (a)
Sol. Any of the object or material which has the highest refractive index has the minimum speed of light. The glass has the highest refractive index among other like, vacuum, water and air. 

S2. Ans. (c)
Sol. The radius of curvature of the plane is infinity. 

S3. Ans. (d)
Sol. Electrical conductivity is a measure of the amount of electrical current under a material can carry. The most electrically conductive element is silver. 

S4. Ans. (d)
Sol. The most common nuclear fuels are uranium – 235 (235U) and plutonium -239(239Pu). Thorium is more abundant in nature than uranium. Thorium can be used as a nuclear fuel through breeding to uranium-233 (U-233). Lead is not used as a nuclear fuel. 

S5. Ans. (d)
Sol. The neon gas is used in discharge lamps, tubes and in fluorescent bulbs.

S6. Ans. (d)
Sol. In 1935 Meson particles were discovered by Japanese physicist Hideki Yukawa. Positron, the antiparticle of the antimatter counterpart of the electron was discovered by C.D. Anderson and U.F. Hess in 1932. In 1939, Hans Bethe described the nuclear reactions that power the sun and other starts. In the synthesis of transuranic elements, Glenn T. Scaborg played an important role instead of Enrico Fermi. The fact is that he attempted to prepare a transuranium element in 1934 in Rome but failed to do so. 

S7. Ans. (b)
Sol. The density of water increases with temperature but volume decreases. At 4°C, the volume of water is low and density is maximum. Conversion of Celsius in Kelvin 
K = C + 273 
= 4 + 273 = 277 
So, the density of water is maximum at 277 K. 

S8. Ans. (d)
Sol. Holography is a technique of producing a three-dimensional image of an object.

S9. Ans. (c)
Sol. Most remote controls of a television receiver send signals using Infra-red radiation.

S10. Ans. (b)
Sol. Option (b) is not correct. It is because the breaking apart of nucleus of an atom is called fission not fusion. Fission is a radioactive decay process in which the nucleus of an atom splits into smaller parts.

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