CDS I 2020 General Knowledge Previous Year Paper (02-Feb-2020)

Question 1

Scattering of a-particles by a thin gold foil suggests the presence of

Accepted Answer

positively charged nucleus at the centre of an atom

Answer

electron in an atom

Answer

proton in an atom

Answer

isotopes of gold

Question 2

The elements of which of the following pairs are isobars?

Accepted Answer

${}_{18}^{40}Ar$ and   ${}_{20}^{40}Ca$

Answer

${}_1^1H$ and  ${}_1^3H$

Answer

${}_1^1H$ and  ${}_1^2H$

Answer

${}_6^{12}C$ and  ${}_6^{14}C$

Question 3

Which one of the following chemical reactions is NOT feasible?

Accepted Answer

$Cu + PbCl_2 \rightarrow CuCl_2 + Pb$

Answer

$Fe + CuSO_4 \rightarrow FeSO_4 + Cu$

Answer

$Zn + CuSO_4 \rightarrow ZnSO_4 + Cu$

Answer

$Mg + CuSO_4 \rightarrow MgSO_4 + Cu$

Question 4

A solution having pH equal to zero is known as

Accepted Answer

highly acidic solution

Answer

highly alkaline solution

Answer

weakly acidic solution

Answer

neutral solution

Question 5

Which one of the following acids is produced in human stomach?

Accepted Answer

Hydrocholoric acid

Answer

Formic acid

Answer

Sulphuric acid

Answer

Nitric acid