CAPF (AC) 2018 (Paper-1) (Question 1-50)

Total Questions: 50

1. The optical phenomenon that is responsible for the propagation of light signal through an optical fibre is

Correct Answer: (c) total internal reflection
Solution:

Internal reflection is the optical phenomenon that is responsible for the propagation of the light signal through an optical fibre. It is used to transmit light rays in the case of the simplest form of optical fibre, light entering one end to the fibre strikes the boundary of the fibre and is reflected inwards. Snell has postulated interesting laws on this optical phenomenon. Hence, the right answer is (c).

2. Which of the following statements about optical microscope is/are correct?

1. Both the eyepiece and objective of a microscope are convex lenses.

2. The magnification of a microscope increases with increase in focal length of the objective.

3. The magnification of a microscope depends upon the length of the microscope tube.

4. The eyepiece of a microscope is a concave lens.

Select the correct answer using the code given below.

Correct Answer: (a) 1 and 3
Solution:

An optical microscope is also known as a light microscope that uses visible light and a system of lenses to generate magnified images of small objects to an enlarged form.

It has two types one is a Simple microscope and the other one is a compound microscope, the previous one has a single lens while the last one has a system of lenses. In an optical microscope, both eyepiece and objective lenses are convex. The magnification of the microscope depends on the length of the tube, not on the focal length. Thus, the right answer is (a).

3. Which one of the following gemstones contains beryllium metal?

Correct Answer: (b) Emerald
Solution:

The most common mineral containing beryllium is beryl which is found in granites and special igneous rocks, derived from granites, known as peganites. It is coloured, transparent. Varieties of beryl may be gems such as emerald (green), morganatic (pink) and aquamarine. Its chemical composition is Be³ Al² Si⁶ O¹⁸ It is mainly found in Colombia, Egypt, Pakistan.

While Ruby is a gem of corundum and is dominant in red colour due to the presence of Chromium. Topaz is a rare silicate mineral. And Blue Sapphire have trace amounts of iron and titanium.

4. Lowering the atmospheric pressure on a liquid

Correct Answer: (b) lowers the boiling point of the liquid
Solution:

The boiling point is the temperature of the substance at which the vapour pressure of the liquid equals the pressure surrounding the liquid. Vapour Pressure is the pressure exerted by the vapour in the thermodynamic equilibrium with its condensed phases at a given temperature in a closed system.

With the raising of atmospheric pressure, the boiling point will raise and conversely lowering the atmospheric pressure will lower the boiling point of the liquid. It happens as the vapour pressure of the liquid varies with the change of temperature.

5. The number of angular and radial nodes for 4d orbital is respectively

Correct Answer: (a) 2 and 1
Solution:

A node in atomic structure is defined as the place in an atom where the probability of finding an electron is zero. In an atom there are two nodes one is radical nodes and the other one is angular nodes.

We know, r = n − 1 – 1, where r is a radical node, n is the principal quantum number and 1 is the azimuthal quantum number. For 4d orbital, n = 4 and 1 = 2

Therefore, r = 4 - 2 - 1 = 1, Then total no. of nodes = 4 - r = 3.then angular nodes = total nodes - radical nodes = 3 - 1 = 2.Thus answer A is the right.

6. Which one of the following statements about proteins in mammalian cells is correct?

Correct Answer: (c) Proteins in mammalian cells are synthesized in rough endoplasmic reticulum.
Solution:

Mammalian cells are those cells that are derived or isolated from the tissues of a mammal. They are Eukaryotic cells that contain a membrane-bound nucleus and vast club cellular compartments called organ cells.

They maintain their shape due to the cytoskeleton which is composed of microtubules intermediate filament and microfilament within the cytoplasm. Cytoplasmic ribosomes that is associated with the rough endoplasmic reticulum synthesis particular membrane and cell organelle proteins and the majority of proteins, all proteins that are secreted out of the cell.

In Mammalian cells, proteins are not synthesized Reticulum (RER) present in the Ribosome, which is responsible for the synthesis and packaging of proteins.

7. Which one of the following statements about transport mechanism in plants is correct?

Correct Answer: (b) Active transport of ions and small molecules across cell membrane against concentration gradient requires energy.
Solution:

Cells conserve energy and no energy is required for the transport of ions and small molecules against concentration gradient cells do not transport ions across their membranes as there are charge molecules.

Active transport is the movement of molecules across a cell membrane from a lower concentration to a region of higher concentration against the concentration gradient. It requires cellular energy to achieve this movement.

In plants there are two types of diffusion process one is passive and another one is active. In a passive diffusion, no energy is required for the movement of a substance across the membrane, while in active diffusion energy is required for movement across the membrane and the energy comes from ATP

8. If the amplitude of oscillation of a simple pendulum is very small, then its time period of oscillation

1. depends on the length of the pendulum, L

2. depends on the acceleration due to gravity, g

3. depends upon the mass of the bob of the pendulum, m

4. does not depend upon the amplitude of the pendulum, A

Select the correct answer using the code given below.

Correct Answer: (b) 1, 2 and 4
Solution:

The Period of Oscillation:

The period is directly proportional to the square root of the length of the simple pendulum, L. It is inversely proportional to the square root of gravity, g. T = [ 1/g, where T stands for the period is the length of oscillating thread and g is the gravity.

The period of oscillation is independent of the mass of the pendulum, m and it is also not dependent on the attitude of the pendulum, A. Hence the right answer is B.

9. The term LASER stands for

Correct Answer: (a) Light Amplification by Stimulated Emission of Radiation
Solution:

The term LASER stands for Light Amplification by stimulated Emission of Radiation. It is a device that stimulates atoms or molecules in away such that the light of some specific wavelengths are produced. Generally, it covers a limited range of visible infrared or ultraviolet wavelengths.

Many different types of devices have lesser and the characteristics have been developed over the years. The rays produced by these gadgets have been beneficial for humans. So they have used these in several ways. Hence, the right answer is (a).

10. Which of the following statements about carboxylic acids is/arc correct?

1. Simple aliphatic carboxylic acids are soluble in water.

2. Higher carboxylic acids are practically insoluble in water.

3. The acidity of a carboxylic acid depends on the number of carbon atoms present in the hydrocarbon chain.

Select the correct answer using the code given below.

Correct Answer: (d) 1, 2 and 3
Solution:

Carboxylic acid is an organic compound that contains a carboxyl group-COOH. Its general formula is RCOOH, where R refers to Alkyl Group is - CH³, - C2H⁵. The acidity of an acid depends on the number of H⁺ ion presents in the group, not on the number of the carbon atom, which shows that tee statement 3 is incorrect.

The acids with less than 5 carbon atoms are easily soluble in the water but acids with a greater number of carbon atoms or acids with more molecular weight are not soluble in water because of the presence of a large hydrocarbon portion in the molecule. Hence, (d) is the right answer.