You are here
Home > Uncategorized > NDA Science Practice Sets

NDA Science Practice Sets


Q1.
The effective resistance of three equal resistances, each of resistance r, connected in parallel, is
(a) 3/r
(b) r/3
(c) 3r
(d) r 3

Q2. If the electrical resistance of a typical substance suddenly drops to zero then the substance is called
(a) superconductor
(b) semiconductor
(c) conductor
(d) insulator

Q3. Which one among the following is the correct order of power consumption for light of equal intensity?
(a) CFL tube < Fluorescent tube < Incandescent bulb < Light emitting diode
(b) Light emitting diode < CFL tube < Fluorescent tube < Incandescent bulb
(c) CFL tube < Fluorescent tube < Light emitting diode < Incandescent bulb
(d) Incandescent bulb < Light emitting diode < Fluorescent tube < CFL tube

Q4. 1. Which type of cell can be used if a device requires 75 A of current for 15 seconds?
(a) Simple voltaic cell
(b) Daniel cell
(c) Leclanche cell
(d) Lead-acid cell

Q5. Which one of the following is the unit of activity of a radioactive source?
(a) Lux
(b) Becquerel
(c) Tesla
(d) Siemens

Q6. Sun emits energy in the form of electromagnetic radiation. The following help in the generation of solar energy. Arrange them in the right sequence beginning from the starting of the cycle:
 1. Hydrogen is converted to helium at very high temperatures and pressures.
 2. The energy finds its way to sun’s surface.
 3. A vast quantity of energy is generated by nuclear fusion.
Select the correct answer using the code given below.
(a) 1-2-3
(b) 2-3-1
(c) 3-2-1
(d) 1-3-2

Q7. Which one of the following noble gases is not found in the atmosphere?
(a) Argon
(b) Krypton
(c) Radon
(d) Xenon

Q8. Which of the following sets of substance can exist as molecular crystalline solids?
(a) Nickel, Zinc, Manganese
(b) Glass, Cement, Rubber
(c) Polyethene, Polyvinyl Chloride, Graphite
(d) Iodine, Sulphur, H2O.

Q9. As compared to covalent compounds, electrovalent compounds, generally have
(a) low melting point and low boiling point
(b) low melting point and high boiling point
(c) high melting point and low boiling point
(d) high melting point and high boiling point

Q10. Which one among the following equations is correctly balanced?
(a) NaOH + Al + H2O ® 2H2 + NaA1O2
(b) 2NaOH + 2A1 + 2H2O ® 3H2 + 2NaA1O2
(c) 2NaOH + 2A1 + 3H2O ® 4H2 + 2NaA1O2
(d) 2NaOH + 2A1 + H2O ® H2 + 2NaA102

Q11. Dry ice is used for making cold-baths in laboratories by mixing with volatile organic solvents. Identify the form of dry ice from the following.
(a) Gaseous carbon dioxide
(b) Liquid carbon dioxide
(c) Solid carbon dioxide
(d) Solid hydrogen oxide

Q12. Assertion (A): Carbon can form more compounds than any other element.
Reason (R): Carbon can exist in various allotropes.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

 
1. (b)2. (a)3. (b)4. c5. (b)6. (d)7. (c)8. 9. (d)10. (b)11. (a)12. (d)

Top
error: Content is protected !!