Science Quiz for NDA: 5th September

Dear Aspirants, Science is an important subject in various exams like NDA, CDS, AFCAT, CAPF and other Police Exams. Here at Defence Adda we provide you with the quizzes based on the syllabus and pattern of these exams. The questions asked are of 10+2 level and preparing with a wide variety of questions will only help you ace in these exams. Here is a quiz based on the latest syllabus of these exams and covering various topics like Quantum Mechanics, Light, Thermodynamics, Magnetism etc to help you prepare with a wide variety of questions.
Q1. Optical fiber works on which of the following principle of light?
(a) Reflection
(b) Refraction
(c) Diffraction
(d) Total internal reflection

Q2. Why does water tank appear shallower when viewed from the top?
(a) Due to reflection
(b) Due to refraction
(c) Due to diffraction
(d) Due to total internal reflection

Q3. Which colour is formed when Red and Green are mixed?
(a) Light blue
(b) Yellow 
(c) White
(d) Grey

Q4. What is the SI unit of frequency?
(a) Newton
(b) Watt
(c)  Farad
(d) Hertz

Q5. RDX was invented by 
(a) Alfred Nobel 
(b) Soddy  
(c) Bergillins 
(d) Henning 

Q6. The two elements that are frequently used for making transistors are
(a)Boron and aluminium
(b)Silicon and germanium
(c)Iridium and tungsten
(d)Niobium and columbium

Q7. Brass gets discoloured in air because of the presence of which of the following gases in air?
(b)Hydrogen sulphide
(c)Carbon dioxide
(d) Nitrogen

Q8.Which of the following is the largest mammal?
(a) Whale
(b) Rhinoceros
(c) Elephant
(d) Human

Q9.What is the full form of RNA?
(a) Ribo Nucleic Acid 
(b) Ribo Nitric Acid 
(c) Ribo Nutrient Acid
(d) Reverse Nucleic Acid

Q10.Which of the following are longest cells of human body?
(a) Pancreatic cells
(b) Epethelial cells
(c) Nerve cells
(d) Epidermal cells


S1. Ans. (d)
Sol. Optical fibre work on the principle of Total Internal Reflection of Light. In optical fibre, when light traveling in an optically dense medium hits a boundary at a steep angle (larger than the critical angle for the boundary), the light is completely reflected. This is called total internal reflection.

S2.Ans. (b)
Sol. Water Tank appears shallower when viewed from the top due to refraction of light. This virtual depth is known as apparent depth.

S3.Ans. (b)
Sol. Yellow colour is formed when Red and Green are mixed.

S4.Ans. (d)
Sol. The SI unit of frequency is the hertz (Hz),  named after the German physicist Heinrich Hertz; one hertz means that an event repeats once per second.

S5. Ans.(d)
Sol. RDX, the abbreviation of this word is Research Department Explosive, is also called cyclonite. It is powerful explosive discovered by Georg Friedrich Henning of Germany and patent in 1898 but not used until World War II when most of the warring powers introduced it. 

S6. Ans.(b)
Sol. Silicon and germanium are frequently used for making transistors.

S7. Ans.(b)
Sol. Brass gets discolored because of the presence of Hydrogen Sulphide in air.

S8. Ans.(a)
Sol. Blue Whale is the largest known mammal

S9. Ans.(a)
Sol. Ribo Nucleic Acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes.

S10. Ans.(c)
Sol. The longest cells in the human body are nerve cells. The longest cells in the human body are the nerve cells whose cell bodies are located in the base of spinal cord and whose axons run down to the ends of toes.

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