TNPSC Science Model Question with Detailed Answer – 1

a. mol
Here the keyword is ‘Symbol’. The Symbol of SI Unit for Amount of Substance is mol whereas the SI Unit of Amount of Substance is mole.

b. Altimeter

Altimeter is mostly used in aircrafts. Ammeter measures the strength of Electric current. Anemometer measures force and velocity of wind and its directions. Audiometer measures the intensity of Sound.

d. Zinc chloride

Copper sulphate is used as insecticide and in electric cells. Sodium Nitrate is a fertilizer. Plaster of Paris is mainly used in Statues and in surgery purposes.

c. I and II

a. Plant uses Oxygen and Produces Carbon dioxide.

It is very important to note that, Photosynthesis is different and Respiration is different. For the process of Photosynthesis, plants intake Carbon dioxide from the atmosphere and uses it with water in presence of Sun Light and the products of Photosynthesis are Glucose, Water and Oxygen.

Normally Respiration denotes the movement of Oxygen into the body of organism (inhale) and release of Carbon dioxide.

Cellular Respiration is the process of reaction of Oxygen with Glucose in the cells of the organisms to produce Energy, Water and Carbon dioxide (this Carbon dioxide is released out).

Hence for respiration, the plants too need Oxygen. Usually, plants uses the Oxygen produced from Photosynthesis process for its respiration instead of getting from atmosphere. The excess Oxygen after using for respiration is given out to the atmosphere. This is generally said as Plants intake Carbon dioxide and gives out Oxygen.

b. Weight of the fluid

(Std 9 – Liquids)

The Buoyant force is also called as Archimedes’ principle as it was said by him. According to it, When a body is immersed in a fluid, (liquid or gas) it experiences an apparent loss of weight which is equal to the weight of the fluid displaced. The reason for the apparent loss of weight we know is the buoyant force.

c. Chemical Energy into Electrical Energy.

An electric cell has two different metal plates called electrodes kept inside a chemical called electrolyte. Due to chemical reaction, one plate develops a positive charge and the other plate develops a negative charge and produces electric current.

d. Furrow Irrigation
(Std 8 – Crop production and management)
The Furrow irrigation method is used in crops like Sugarcane, Banana, Paddy.

Furrow Irrigation

Basin irrigation: In this method the field is just filled with water. (e.g Paddy)
Sprinkler irrigation: This irrigation is used where the soil cannot retain water for a long time. Here the water is sprinkled by sprinklers. e.g. Lawn
Drip irrigation: In this irrigation the water falls drop by drop directly at the position of the roots, so it is called drip irrigation. It is the best method to save water. It helps to irrigate grapes, banana, brinjal, etc.

c. Stomata

a. Exothermic Reaction

(Std 10 – Chemical Reaction)

The chemical reactions which take place with the evolution of heat energy are called exothermic reactions.

N₂ + 3H₂ ? 2NH₃ + Heat

The chemical reactions which take place with the absorption of heat energy are called endothermic reactions.

2NH₃ + Heat ? N₂ + 3H₂

The Chemical Reaction in which both the Oxidation and Reduction takes place is called as Redox reactions.

c. Dermis

(Std 9 – Human Body Organ System)

The skin is like an envelope and its complex structure is divided into three layers of tissues: 1.Epidermis 2.Dermis 3.Hypodermis

Epidermis is the upper layer of the skin. The outermost layer consists of flat, thin and scale – like dead cells. It is separated from the dermis by the basement membrane.

The dermis is the middle layer. It is thick but elastic. The dermis consists of nerves, blood vessels, hair follicles, sweat glands and sebaceous glands (oil glands). Sweat glands separate sweat from the blood.

It is the innermost layer of the skin. It is thick and contains large amounts of adipose tissue.

a. Carbon monoxide

(Std 8 – Air, Water and Soil Pollution)

Carbon dioxide leads to Global warming. Nitrogen oxides from automobile exhaust cause acid rain. Sulphur dioxide causes irritation in the eyes, lung cancer and asthma.

c. 11 and 19 years of age

(Std 8 – Reaching the age of adolescence)

d. 4 3 1 2