SSC CHSL 2017 PYQs

Question 1

Sponges belongs to the phylum

Accepted Answer

Sponges are simple multicellular animals characterized by pores, belonging to the phylum Porifera. This is a direct classification fact.

Question 2

Spiders belong to the phylum

Accepted Answer

Spiders are invertebrates with an exoskeleton, segmented bodies, and jointed appendages, which are defining characteristics of the phylum Arthropoda.

Question 3

Rodentia Sciurus is the scientific name of

Accepted Answer

Rodentia Sciurus is the scientific name for a squirrel. This binomial nomenclature identifies the genus (Sciurus) and order (Rodentia) of the animal.

Question 4

What is the full form of PVC?

Accepted Answer

PVC stands for Polyvinyl Chloride, a widely used synthetic plastic polymer. It is commonly used in pipes, window frames, and electrical cable insulation.

Question 5

Which among the following is false about alpha particles?

Accepted Answer

Alpha particles have low penetrating power due to their large mass and charge, which causes them to interact frequently with matter and lose energy quickly.

Question 6

What does a catalyst do in a reaction?

Accepted Answer

A catalyst provides an alternative reaction pathway with lower activation energy, thereby increasing the reaction rate without being consumed.

Question 7

The mass of proton and mass of which atomic particle is  same?

Accepted Answer

Protons and neutrons have approximately the same mass, which is about 1 atomic mass unit (amu). Electrons are significantly lighter.

Question 8

Which among the following is present inside the nucleus of an atom?

Accepted Answer

The nucleus of an atom contains protons and neutrons. Electrons orbit the nucleus in shells. This is a fundamental concept in atomic structure.

Question 9

Analgesics ________.

Accepted Answer

Analgesics are a class of drugs specifically designed to relieve pain. They work by blocking pain signals or reducing inflammation.

Question 10

Which among the following is an endothermic reaction?

Accepted Answer

Endothermic reactions absorb heat from their surroundings. Sweating cools the body by absorbing heat for evaporation, making it an endothermic process.

Question 11

Release of which among the following is the primary reason for depletion of the ozone layer?

Accepted Answer

Chlorofluorocarbons (CFCs) are the primary chemicals responsible for the depletion of the ozone layer, commonly found in refrigerants and aerosols.

Question 12

Which among the following has the maximum density?

Accepted Answer

Water has maximum density at 4°C. Ice is less dense than water, which is why it floats. Ethylene and Acetone have lower densities.

Question 13

The reactions in which oxidation and reduction occur simultaneously are called _______.

Accepted Answer

Redox reactions are defined as chemical reactions where both oxidation (loss of electrons) and reduction (gain of electrons) processes occur simultaneously.

Question 14

Aromatic hydrocarbons contain at least how many  benzene rings in their molecules?

Accepted Answer

Aromatic hydrocarbons are defined by the presence of at least one benzene ring in their molecular structure, which imparts their characteristic properties.

Question 15

Which among the following is not a characteristic of oxidation reaction?

Accepted Answer

Oxidation is defined as the addition of oxygen, removal of hydrogen, or loss of electrons. Therefore, addition of hydrogen is not a characteristic of oxidation.

Question 16

Adding which substance gives green colour to glass?

Accepted Answer

Chromium oxide is specifically used as a coloring agent to impart a green hue to glass. It's a direct application of chemical properties.

Question 17

Using which of the following processes can one separate  a solute from its solution?

Accepted Answer

Evaporation is the process where a liquid turns into a gas, leaving the dissolved solid (solute) behind. This effectively separates the solute from its solution.

Question 18

What is baking soda?

Accepted Answer

Baking soda is chemically known as sodium bicarbonate. Its chemical formula is NaHCO₃. It is commonly used in baking as a leavening agent.

Question 19

Atomic number of which of the following elements is greater than that of Calcium?

Accepted Answer

Calcium has an atomic number of 20. Among the given options, Scandium has an atomic number of 21, which is greater than Calcium.

Question 20

Name the catalyst used in the conversion of milk into curd.

Accepted Answer

Lactase is the enzyme that breaks down lactose (milk sugar) into glucose and galactose, a key step in curd formation. Pepsin is for protein digestion.