General Science · NDA previous year questions

Which one of the following is NOT a synthetic detergent?

1. A.$\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_{10}\mathrm{C}{\mathrm{H}}_2\mathrm{OS}{\mathrm{O}}_3^{-}\mathrm{N}{\mathrm{a}}^{+}$
2. B.$[\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_{15}-\mathrm{N}-(\mathrm{C}{\mathrm{H}}_3{)}_3{]}^{+}\mathrm{B}{\mathrm{r}}^{-}$
3. C.$\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_{16}\mathrm{CO}{\mathrm{O}}^{-}\mathrm{N}{\mathrm{a}}^{+}$
4. D.$\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_{16}\mathrm{COO}(\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{O}{)}_{\mathrm{n}}\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{OH}$

Which one of the following is an example of a clean fuel?

1. A.Coke
2. B.Propane
3. C.Petrol
4. D.Wax

Basic scientific principle behind a nuclear reactor is

1. A.Nuclear fusion
2. B.Controlled nuclear fusion
3. C.Uncontrolled nuclear fission
4. D.Controlled nuclear fission

Which one of the following could be the melting point of iron?

1. A.25°C
2. B.37°C
3. C.500°C
4. D.1500°C

Which one of the following substances is NOT a mixture ?

1. A.Ice
2. B.Ice-cream
3. C.Air
4. D.Honey

As per the code of the nomenclature, which one of the following is the correct way of writing a biological name?

1. A.$\text{Amoeba Proteus}$
2. B.$\text{Amoeba proteus}$
3. C.$\text{amoeba proteus}$
4. D.$\underline{\text{Amoeba}}\underline{\text{Proteus}}$

The Sun is seen little before it rises and for a short while after it sets. This is because of

1. A.total internal reflection
2. B.atmospheric refraction
3. C.apparent shift in the direction of Sun
4. D.dispersion

Which one of the following is the correct relation between Å and nm?

1. A.1 nm $=10^{-1}$ Å
2. B.1 nm = 10 Å
3. C.1 nm = 1 Å
4. D.1 nm $=10^{-2}$ Å

1. A.$\theta ={\sin }^{-1}(1/9.8)$
2. B.$\theta ={\sin }^{-1}(1/20)$
3. C.$\theta ={\sin }^{-1}(1/80)$
4. D.$\theta ={\sin }^{-1}(1/100)$

The coefficient of areal expansion of a material is $1.6\times 10^{-5}{\mathrm{K}}^{-1}$. Which one of the following gives the value of coefficient of volume expansion of this material?

1. A.$0.8\times 10^{-5}{\mathrm{K}}^{-1}$
2. B.$2.4\times 10^{-5}{\mathrm{K}}^{-1}$
3. C.$3.2\times 10^{-5}{\mathrm{K}}^{-1}$
4. D.$4.8\times 10^{-5}{\mathrm{K}}^{-1}$

Which one of the following is called 'syngas'?

1. A.$\mathrm{C}(\mathrm{s})+{\mathrm{H}}_2\mathrm{O}(\mathrm{g})$
2. B.$\mathrm{CO}(\mathrm{g})+{\mathrm{H}}_2\mathrm{O}(\mathrm{g})$
3. C.$\mathrm{CO}(\mathrm{g})+{\mathrm{H}}_2(\mathrm{g})$
4. D.$\mathrm{N}{\mathrm{O}}_2(\mathrm{g})+{\mathrm{H}}_2(\mathrm{g})$

Which one of the following is not used as fertilizer?

1. A.Ammonium nitrate
2. B.Ammonium sulphide
3. C.Ammonium phosphate
4. D.Ammonium sulphate

Which one of the following depicts the correct circuit of a reflex arc?

1. A.Effector—sensory neuron—spinal cord—motor neuron—receptor
2. B.Receptor—sensory neuron—spinal cord—motor neuron—effector
3. C.Receptor—sensory neuron—brain—motor neuron—effector
4. D.Sensory neuron—receptor—brain—effector—motor neuron

A ball balanced on a vertical rod is an example of

1. A.stable equilibrium
2. B.unstable equilibrium
3. C.neutral equilibrium
4. D.perfect equilibrium

Which one of the following statements about the refractive index of a material medium with respect to air is correct?

1. A.It can be either positive or negative
2. B.It can have zero value
3. C.It is unity for all materials
4. D.It is always greater than one

Brine is an aqueous solution of

1. A.$\mathrm{NaCl}$
2. B.$\mathrm{NaOH}$
3. C.$\mathrm{NaHC}{\mathrm{O}}_3$
4. D.$\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3$

Which one of the following parts of body does NOT take part in the process of breathing?

1. A.Bronchi
2. B.Bowman’s capsule
3. C.Diaphragm
4. D.Trachea

If some object is weighed when submerged in water, what will happen to its weight compared to its weight in air?

1. A.Increase
2. B.Decrease
3. C.Remain exactly the same
4. D.Increase or decrease cannot be predicted

The symbol of SI unit of inductance is H. It stands for

1. A.Holm
2. B.Halogen
3. C.Henry
4. D.Hertz

In a vacuum, a five-rupee coin, a feather of a sparrow bird and a mango are dropped simultaneously from the same height. The time taken by them to reach the bottom is $t_1$, $t_2$ and $t_3$ respectively. In this situation, we will observe that

1. A.$t_1>t_2>t_3$
2. B.$t_1>t_3>t_2$
3. C.$t_3>t_1>t_2$
4. D.$t_1=t_2=t_3$

Radioactivity is measured by

1. A.GM Counter
2. B.Polarimeter
3. C.Calorimeter
4. D.Colorimeter

Why is potassium permanganate used for purifying drinking water?

1. A.It kills germs
2. B.It dissolves the impurities
3. C.It is a reducing agent
4. D.It is an oxidizing agent

When pure water boils vigorously, the bubbles that rise to the surface are composed primarily of

1. A.air
2. B.hydrogen
3. C.hydrogen and oxygen
4. D.water vapour

An optical illusion which occurs mainly in deserts during hot summer is based on the principle of

1. A.Reflection
2. B.Interference
3. C.Dispersion
4. D.Total internal reflection

Which one of the following statements is correct about the magnification of an optical microscope ?

1. A.Magnification increases with the increase in focal length of eyepiece
2. B.Magnification increases with the increase in focal length of objective
3. C.Magnification does not depend upon the focal length of eyepiece
4. D.Magnification decreases with the increase in focal length of eyepiece