Exercise 2.1 Which of the following expressions are polynomials in one variable and which are not? State reasons for your answer:-(i) 4×2– 3x + 7(ii) y2+√2(iii) 3√t+t√ 2(iv) y+(v) x10+y3+t50Sol:- (i) 4×2–3x+7 is a polynomial in one variable. The equation 4×2–3x+7 can be written as 4×2–3×1+7×0 and since x is the only variable in the given equation […]
Exercise 1.1 Is zero a rational number? Can you write it in the form p/q,where p and q are integers and q ≠0 ?Ans:- Yes zero is a rational number.we can write zero as :-0/1, 0/2Thus we can write 0 in the form of p/q where p and q are integers and q ≠0 . Hence, […]
In-Text Questions Solutions In Text-Questions Page 148 A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?Ans:- When a force […]
In-Text Questions Solutions In Text-Questions Page 134 State the universal law of gravitation.Ans:- According to universal law of gravitation, every particle in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of distance between them. The direction of force […]
In-Text Questions Solutions In Text-Questions Page 118 Which of the following has more inertia:(a) a rubber ball and a stone of the same size? (b) a bicycle and a train?(c) a five rupees coin and a one-rupee coin?Ans:- (a) Mass of a stone is more than the mass of a rubber ball of same size. […]
In-Text Questions Solutions In-Text Questions Page 32 In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass. sodium carbonate […]
In-Text Questions Solutions In Text-Questions Page 100 An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.Ans:- Yes, an object moving through a distance can have zero displacement. This happens when final position of the object coincides with its initial position. For example, if a […]
NCERT In-Text Questions Solutions In-Text Questions Page 15 What is meant by a pure substance?Ans:- A pure substance consists of a single type of particles that cannot be separated into other kinds of matter by any physical process. List the points of differences between homogeneous and heterogeneous mixtures.Ans:- Differences between homogeneous and heterogeneous mixture: S. […]
NCERT In-Text Questions Solutions In-Text Questions Page 80 Why do we classify organisms?Ans:- For easier and convenient study we classify organisms. Give three examples of the range of variations that you see in lifeforms around you.Ans:- (a) Small cat and big cow(b) Grass and banyan tree (c) Black crow and green parrot In-Text Questions Page […]
NCERT In-Text Questions Solutions In-Text Questions Page 69 what is tissue?Ans:- A group of cells that are similar in structure and perform a particular function is called tissue. What is the utility of tissues in multi-cellular organisms?Ans:- Tissues provide structural strength, mechanical strength, show division of labour. In-Text Questions Page 74 Name types of simple […]