Revision Series | Science | General Science | 18

October 25, 2023

Which of the following are living characters of a virus?
1. They respond to heat, chemicals and radiations.
2. They reproduce inside the host cells and produce copies of themselves.
3. They are inactive when present freely in the environment. 4. They can be crystallized and stored for a very long time.
Choose the correct answer using the codes given below:

(A) 1 and 2 only
(B) 2 and 3 only
(C) 1 and 4 only
(D) 3 and 4 only

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Answer- A

Characteristics of Virus

Viruses show both living and non-living characters.

Living characters

They respond to heat, chemicals and radiations.
They reproduce inside the host cells and produce copies of themselves.

Non-living characters

They are inactive when present freely in the environment.
They can be crystallized and stored for a very long time, like other non-living things.

What are the female hormones secreted by ovaries in human beings?

(A) Testosterone and estrogen
(B) Estrogen and progesterone
(C) Testosterone and progesterone
(D) Estrogen and prolactin

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Answer- B

Estrogen and progesterone

Explanation: Testosterone is a male hormone produced by testes; estrogen and progesterone are female hormones produced by ovaries.

Assertion : Force is a derived physical quantity.
Reason : Force cannot be derived from the fundamental physical quantities.

(A) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(B) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(C) If Assertion is correct but Reason is incorrect.
(D) If Assertion is incorrect but Reason is correct.

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Answer- C

Flow velocities in an incompressible fluid can be measured with which one of the following?

(A) Barometer
(B) Venturi tube
(C) Strain gauge
(D) Manometer

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Answer- B

The chemical used as fixer in the photography is –

(A) Sodium thiosulphate
(B) Borax
(C) Sodium tetrathionate
(D) Ammonium molybdate

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Answer- A

Sodium thiosulphate (Hypo) is used in photography as a fixer of positive and negative. It is also used in the extraction of Gold and Silver.

Which organelle in the cell, other than the nucleus, contains DNA ?

(A) Centriole
(B) Lysosome
(C) Golgi apparatus
(D) Mitochondrion

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Answer- D

Besides the nucleus, DNA is also found in the mitochondria and chloroplast of cells, which is a genetic material and carries the symptom signs of creatures to descendants from a parent like a horoscope.

Assertion (A) : A myopic person is advised to use concave lens.
Reason (R) : The eye lens of a myopic person focuses the parallel rays coming from distant objects in front of the retina.

(A) Both A and R are individually true and R is the correct explanation of A
(B) Both A and R are individually true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false but R is true

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Answer- A

Light Emitting Diode (LED) converts

(A) Light energy into electrical energy
(B) Electrical energy into light energy
(C) Thermal energy into light energy
(D) Mechanical energy into electrical energy

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Answer- B

It is an optical semiconductor device that emits light when voltage is applied means it converts electrical energy into light energy.

When Light Emitting Diode (LED) is forward biased, the free electrons from the n-side and the holes from the p-side are pushed towards the junction.

Which one of the following elements exist in liquid state at room temperature?

(A) Hydrogen
(B) Bromine
(C) Oxygen
(D) Iodine

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Answer- B

Bromine is an element with symbol Br and atomic no. 35. It is the third lightest halogen and is a fuming liquid with deep red colour. It is the only non-metallic element to exist in the liquid state at room temperature.

Match the column - I and Column - II.
Column-I = Column-II
A. Myopia = P. Convex lens
B. Hypermetropia = Q. Concave lens
C. Presbyopia = R. Cylindrical lens
D. Astigmatism = S. Bifocal Lens

(A) A-P; B-Q; C-S; D-R
(B) A-P; B-Q; C-R; D-S
(C) A-Q; B-P; C-S; D-R
(D) A-Q; B-P; C-R; D-S

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Answer- c