Archives

Choose the correct option. Justify your choice. (1 + tan θ + sec θ) (1 + cot θ – cosec θ) =?. (A) 0 (B) 1 (C) 2 (D) – 1

Answer: (C) 2 (1 + tan θ + sec θ) (1 + cot θ – cosec θ) We know that, tan θ = sin θ/cos θ sec... View Article

Choose the correct option. Justify your choice. (sec A + tan A) (1 – sin A) =? (A) sec A (B) sin A (C) cosec A (D) cos A

Answer: (D) cos A We know that, sec A= 1/cos A tan A = sin A / cos A Now, substitute the above values in the given problem, we get (secA +... View Article

Choose the correct option. Justify your choice. 1 + tan²A/1 + cot²A =? (A) sec2 A (B) -1 (C) cot2A (D) tan2A

Answer: (D) tan2A We know that, tan2A =1/cot2A Now, substitute this in the given equation, we get 1 + tan2A/1 + cot2A = (1 + 1/cot2A)/1 + cot2A =... View Article

Choose the correct option. Justify your choice. 9 sec²A – 9 tan²A =? (A) 1 (B) 9 (C) 8 (D) 0

Answer: (B) 9 9 sec2A – 9 tan2A Take 9 outside, and it becomes = 9 (sec2A – tan2A) ∵ sec2 A – tan2 A = 1 = 9×1 = 9... View Article

Classify the changes involved in the following processes as physical or chemical changes: (a) Photosynthesis (b) Dissolving sugar in water (c) Burning of coal (d) Melting of wax (e) Beating aluminium to make aluminium foil (f ) Digestion of food

Answer: Physical change - A substance is said to undergo a physical change when only the physical properties such as the shape, size, colour,... View Article

Classify the following as linear, quadratic and cubic polynomials: 1 + x

Answer: Linear polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: 3t

Answer: Linear polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: 7x³

Answer: Cubic polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: r²

Answer: Quadratic polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: x – x³

Answer: Cubic polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: x² + x

Answer: Quadratic polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following as linear, quadratic and cubic polynomials: y + y² + 4

Answer: Quadratic polynomial A polynomial is an algebraic expression in which the exponent on any variable is a whole number. Polynomial’s... View Article

Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories? x + y, 1000, x + x² + x³ + x⁴ , 7 + y + 5x, 2y – 3y² , 2y – 3y² + 4y³ , 5x – 4y + 3xy, 4z – 15z2 , ab + bc + cd + da, pqr, p²q + pq² , 2p + 2q.

Answer: Polynomials are algebraic expressions that consist of variables and coefficients. Polynomials are of 3 different types and are... View Article

Cleaning of water is a process of removing ____________.

Answer: Cleaning of water is a process of removing pollutants. The process of removing pollutants from water before it enters any water... View Article

Consider the list of terms given below (i) Tsunami (ii) Landslide (iii) Floods (iv) Lightning Earthquakes can cause (a) (i), (ii) & (iii) (b) (ii) & (iv) (c) (ii), (iii) & (iv) (d) (iii) & (iv)

Answer: (a) (i), (ii) & (iii) An earthquake is a sudden shaking or trembling of the earth caused by the collision of the earth's plates or... View Article

Consider the list of terms given below: (i) Seismic Zone (ii) Fault Zone (iii) Mantle (iv) Inner Core The boundaries of the earth’s plate are known as (a) (i) & (ii) (b) (i) & (iii) (c) (iii) & (iv) (d) (ii), (iii) & (iv)

Answer: (a) (i) & (ii) An earthquake is a quick trembling or shaking of the earth that lasts only for a short period. Movement of plates are... View Article

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Archives

Choose the correct option. Justify your choice. (1 + tan θ + sec θ) (1 + cot θ – cosec θ) =?. (A) 0 (B) 1 (C) 2 (D) – 1

Choose the correct option. Justify your choice. (sec A + tan A) (1 – sin A) =? (A) sec A (B) sin A (C) cosec A (D) cos A

Choose the correct option. Justify your choice. 1 + tan²A/1 + cot²A =? (A) sec2 A (B) -1 (C) cot2A (D) tan2A

Choose the correct option. Justify your choice. 9 sec²A – 9 tan²A =? (A) 1 (B) 9 (C) 8 (D) 0

Classify the changes involved in the following processes as physical or chemical changes: (a) Photosynthesis (b) Dissolving sugar in water (c) Burning of coal (d) Melting of wax (e) Beating aluminium to make aluminium foil (f ) Digestion of food

Classify the following as linear, quadratic and cubic polynomials: 1 + x

Classify the following as linear, quadratic and cubic polynomials: 3t

Classify the following as linear, quadratic and cubic polynomials: 7x³

Classify the following as linear, quadratic and cubic polynomials: r²

Classify the following as linear, quadratic and cubic polynomials: x – x³

Classify the following as linear, quadratic and cubic polynomials: x² + x

Classify the following as linear, quadratic and cubic polynomials: y + y² + 4

Classify the following polynomials as monomials, binomials, trinomials. Which polynomials do not fit in any of these three categories? x + y, 1000, x + x² + x³ + x⁴ , 7 + y + 5x, 2y – 3y² , 2y – 3y² + 4y³ , 5x – 4y + 3xy, 4z – 15z2 , ab + bc + cd + da, pqr, p²q + pq² , 2p + 2q.

Cleaning of water is a process of removing ____________.

Consider the list of terms given below (i) Tsunami (ii) Landslide (iii) Floods (iv) Lightning Earthquakes can cause (a) (i), (ii) & (iii) (b) (ii) & (iv) (c) (ii), (iii) & (iv) (d) (iii) & (iv)

Consider the list of terms given below: (i) Seismic Zone (ii) Fault Zone (iii) Mantle (iv) Inner Core The boundaries of the earth’s plate are known as (a) (i) & (ii) (b) (i) & (iii) (c) (iii) & (iv) (d) (ii), (iii) & (iv)

Describe an activity to show that thermoplastic is a poor conductor of electricity

Describe how crystals of copper sulphate are prepared.

Describe the process of neutralisation with the help of an example.

Describe with the help of a diagram an instrument which can be used to detect a charged body.