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Examine whether the following are polygons. If anyone among these is not, say why?

(a) As it is not a closed figure, therefore, it is not apolygon. (b) It is a polygon because it is closed by linesegments. (c) It is not a... View Article

Identify the smallest ion among the following: i) Al³⁺ ii) Na⁺ iii) Ba²⁺ iv) Mg²⁺

The correct answer is option (i) - Al3+ More the nuclear charge on ion, electrons are more strongly attracted and thus size decreases. Hence,... View Article

Why is variation beneficial to the species but not necessarily for the individual?

Answer: Variations are important for species survival because variation causes the organism to overcome extreme situations. Organism species... View Article

Do you think that it is better to use compost instead of chemical fertilizers? Why

Yes, it is better to use compost instead of chemical fertilizers. It is how farm waste material like livestock excreta, vegetable waste,... View Article

If a plant has fibrous roots, what type of venation are its leaves likely to have?

Plants with fibrous roots have parallel venation in their leaves. For example, grass, wheat maize, etc., have fibrous roots with parallel... View Article

Calculate the number of molecules of Sulphur (S₈) present in 16 g of solid Sulphur.

We have to find the number of molecules present in 16g of solid sulphur. The molecular mass of the sulphur molecule is 32 × 8 = 256 u. 1 mole... View Article

Identify the amphoteric oxide from the following: i) Al₂O₃ ii) SO₂ iii) P₂O₅ iv) CaO

Amphoteric oxides like aluminium oxide react with both acids and bases. Amphoteric oxides react with both acids and alkalis to form salt and... View Article

Convert into mole. (a) 12 g of oxygen gas(b) 20 g of water (c) 22 g of carbon dioxide

Answer: A mole is defined as the amount of a substance that contains exactly 6.02214076 × 1023 elementary entities of the given substance. A... View Article

Which amongst the following contains triple bond? i) C₂H₃ ii) C₂H₂ iii) C₂H₄ iv) C₃H₄

CH≡CH is the structural formula of C2H2, so the C2H2 contains a triple bond Triple bond, in chemistry, a covalent linkage in which two atoms... View Article

Which of the following will not represent zero: (a) 1 + 0 (b) 0 x0 (c) 0/2 (d) 10-10/2

Answer: (a) 1 + 0 1+0 =1 ≠ 0 It does not represent zero. 0 x 0 = 0 It represents zero. 0/2 = 0 It Represents zero. (10-10)/ 2 = 0 It... View Article

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

Answer: In birds and mammals have a double circulation system where both the oxygenated and deoxygenated blood maintains separate.... View Article

What are the limitations of extracting energy from – (a) the wind? (b) Waves? (c) Tides?

a)The wind A windmill requires a wind of speed more than 15 km/h to generate electricity from wind energy also large numbers of windmills are... View Article

Select conductor of heat from the following: i) Paper ii)Aluminium iii) Plastic iv) Rubber

(ii) Aluminium is a conductor of heat. Aluminium is an excellent heat and electricity conductor and, concerning its weight, is almost twice... View Article

Which of the following lay eggs? i) Platypus and Echidna ii) Humans iii) None of the above

Platypus and Echidna The platypus echidnas are the world's only monotremes or egg-laying mammals. There are two species of echidnas, one... View Article

Answer: (iii) Dacron Dacron is a condensation polymer. The condensation polymers are formed by repeated condensation reaction between two... View Article

The countries bordering North India are: i) Pakistan ii) Nepal iii) Bhutan iv) All of the above

All of the above India is located in the Southern part of Asia. It is the second-largest country in South- East Asia. It is in the Northern... View Article

Purine derivative among the following bases is: i) Guanine ii) Cytosine iii) Uracil iv) Thymine

Guanine Purine is a heterocyclic aromatic organic compound composed of a pyrimidine ring fused with an imidazole ring. Pyrimidine is a... View Article

Differentiate between parenchyma, collenchyma and sclerenchyma, on the basis of their cell wall.

Tissue provides structural strength, mechanical strength and shows division of labour. A collective number of tissues form organs in the... View Article

Chromosomes are arranged along the equator during a) prophase b)metaphase c)anaphase d)telophase

Answer: (b) metaphase During metaphase chromosomes are arranged on a plane which is known as an equatorial plate. Metaphase is a stage in which... View Article

An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.

Answer: Given An electric iron of resistance 20 Ω takes a current of 5 A Find out We have to calculate the heat developed in 30 s. Solution... View Article