Mix Test - 1

Hydrocarbons are non-biodegradable pollutants. They are a type of secondary pollutants. They are very dangerous for life. Hydrocarbons are produced naturally as well as due to incomplete combustion of the fuels. They are the major cause of respiratory disorders. The man used fuel for their own purpose with releases harmful gases and causes pollution.

Hence, the correct option is (D).

Metals that are more reactive than hydrogen can replace it with acids and form a salt.

In the given options, only Sodium is the metal that is more reactive than hydrogen and can thus, take part in metal-displacement.

Hence, the correct option is (B).

Food preservation is the prevention of growth of bacteria, fungi and other microorganisms in food items.

There are different methods of preserving food. For example, packaging, smoking, drying, pickling etc. Food preservation also prevents spoilage of food and increase their shelf life.

Hence, the correct option is (B).

Given that:

Refractive index \((\mu)=1.5\)

Angle of incidence (i) \(=50^{\circ}\)

\(c=\sin ^{-1}\left(\frac{1}{1.5}\right)=41.8^{\circ}\)

\(\therefore i>c\)

The given light ray, therefore, undergoes total internal reflection as shown:

\(\angle A N O=\angle B N O=50^{\circ}(\because\) angle of incidence \(=\) angle of reflection \()\)

\(\angle A N O=\angle M N P=50^{\circ}(\because\) vertically opposite angle \()\)

Therefore deviation = difference between incident and reflected angles

Deviation \(=180^{\circ}-\left(50^{\circ}+50^{\circ}\right)=80^{\circ}\)

Hence, the correct option is (C).

Influenza is mostly transmitted via air-borne droplets or by contact with infected persons or objects.

Cholera is transmitted by contaminated water which contains bacteria from the faeces of infected persons. It is most likely to happen after a natural disaster which disables the sewage system.

Typhoid is transmitted by contaminated water which contains bacteria from the faeces of infected persons. It is most likely to happen after a natural disaster that disables the sewage system.

So, the correct answer is 'Typhoid and Cholera'.

Hence, the correct option is (D).

The SI unit of thrust is Newton in the SI unit and Dyne in the cgs unit.

The force acting perpendicular to the surface of the object is called thrust. When any object is put into the water then the object will replace the water the same as it’s volume and the cause of which there is a force acting upwards, to balance this weight is called the thrust force.

Thrust is a kind of pull force, which is applied by the medium on the object. It is a type of force so the SI unit of thrust is Newton (N). The effect of thrust is more on the smaller surface area than the thrust acting on a larger surface area. 

Thrust Force (FT) = Pressure (P) × Area (A)

• The SI unit of pressure is the pascal or Newton per meter square.
• The SI unit of momentum is N m.
• The SI unit of surface tension is N/m.

Hence, the correct option is (A).

If a body is moved from position A to another position B on a rough table, work done against frictional force shall depend on the length of the path between A and B and not only on the position A and B.

Therefore, in non-conservative force work done by or against the force in moving a body from one position to another, depends on the path followed between these two positions.

Hence, the correct option is (B).

Iodine: Iodine is a chemical element with symbol 'I' and atomic number 53.

• Iodine Tincture contains iodine which is an antiseptic. It is for use on minor wounds, cuts and scrapes.

Mercury: Mercury is a chemical element with the symbol Hg and atomic number 80.

• Mercury is the only one in the liquid state at room temperature.
• It's used in thermometers because it has a high coefficient of expansion.
• Hence, the slightest change in temperature is notable when it's used in a thermometer.

Aluminium: Aluminium is a chemical element with symbol Al and atomic number 13.

• It is the third most abundant element in the earth crust after Oxygen and Silicon.
• It is used to create food-grade packing materials.

Chlorine: This a chemical element with symbol Cl and atomic number 17.

• It is used to disinfect water and is part of the sanitation process for sewage and industrial waste.

The correct match for the above given:

Hence, the correct option is (D).

Here, u is object distance for first lens, \(v_1\) is image distance formed by first lens and this act as object distance for second lens. Also \(v\) is final image distance.

\(\frac{1}{v_{1}}-\frac{1}{u}=\frac{1}{f_{1}}\)

\(\frac{1}{v}-\frac{1}{v_{1}}=\frac{1}{f_{2}}\)

\(\frac{1}{v}-\frac{1}{u}=\frac{1}{f_{1}}+\frac{1}{f_{2}}\)

\(\frac{1}{v}=\frac{1}{f_{1}}+\frac{1}{f_{2}}+\frac{1}{u}\)

\(\frac{1}{v}=\frac{f_{1} u+f_{2} u+f_{1} f_{2}}{f_{1} f_{2} u}\)

\(v=\frac{f_{1} f_{2} u}{f_{1} u+f_{2} u+f_{1} f_{2}}\)

Hence, the correct option is (C).

Fresh water protozoan usually live in hypotonic environment and the incoming water through endosmosis is regulated by CONTRACTILE vacuoles but when they are kept in a hypertonic water CONTRACTILE vacuoles disappear because of lack of endosmosis and thus water does not enters the protoplasm.

Hence, the correct option is (B).