Match the terms of column A with
Question: Match the terms of column A with those of column B. Solution: a IIi, b iv, c i, d ii....
Read More →Label the parts of a neuron shown in the figure.
Question: Label the parts of a neuron shown in the figure. Solution: a Dendrite. b Cyton (Cell body). c Axon. d Axon terminal (bouton)....
Read More →In the figures (a), (b) and (c)
Question: In the figures (a), (b) and (c) which appears more accurate and why ? Solution: Figure (a) is more accurate as it shows appropriate response of both shoot and root to the vector of gravity. Shoot is negatively geotropic. It, therefore, bends upwardly. Root is positively geotropic. It, therefore, bends downwardly....
Read More →Label the endocrine glands in the figure
Question: Label the endocrine glands in the figure Solution: a Pineal gland. b Pituitary gland. c Thyroid d Thymus....
Read More →Name the plant hormone responsible for the following :
Question: Name the plant hormone responsible for the following : (a) Elongation of cells (b) Growth of stem (c) Promotion of cell division (d) Falling of senescent leaves. Solution: (a) Elongation of Cells. Auxin. (b) Growth of Stem. Gibberellin. (c) Promotion of Cell Division. Cytokinin. (d) Falling of Senescent Leaves. Abscisic acid....
Read More →1. Label the parts a, b, c and d and show the direction
Question: 1. Label the parts a, b, c and d and show the direction of electrical signals in the figure. (CBSE 2010) 2. Draw the figure shown here and label motor neuron, relay neuron and spinal cord. What is the name of this connection ?(CCE 2011) Solution: a Sensory neuron.b Spinal cord (CNS).c Mortor neuron.d Effector (muscle in arm) Name Reflex arc.Direction : Receptor (hand) to spinal cord through sensory neuron, Sensory neuron to motor neuron through Spinal cord to effector through motor neu...
Read More →The list price of a refrigerator is Rs 14650.
Question: The list price of a refrigerator is Rs 14650. If 6% is charged as sales tax, find the cost of the refrigerator. Solution: List price of the refrigerator =Rs 14650 Sales tax = 6% of Rs 14650 $=\operatorname{Rs}\left(14650 \times \frac{6}{100}\right)$ $=\operatorname{Rs} 879$ Bill amount $=$ Rs $(14650+879)$ $=\operatorname{Rs} 15529$ Hence, the cost of the refrigerator is Rs 15,529....
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $e^{x \log x}$ Solution: Let $y=e^{x \log x}$ Taking log both the sides: $\Rightarrow \log y=\log (e)^{x \log x}$ $\Rightarrow \log y=x \log x \log e\left\{\log x^{a}=\operatorname{alog} x\right\}$ $\Rightarrow \log y=x \log x\{\log e=1\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}(\mathrm{x} \log \mathrm{x})}{\mathrm{dx}}$ $\Rightarrow \frac{d(\...
Read More →Find the single discount which is equivalent to
Question: Find the single discount which is equivalent to two successive discounts of 20% and 5%. Solution: Let the marked price of the article be Rs 100. First discount = 20% Price after the first discount = (100 20) = Rs 80 Second discount = 5% of 80 $=\frac{5}{100} \times 80$ $=\operatorname{Rs} 4$ Price after the second discount = (80 4) = Rs 76 Net selling price = Rs 76 Single discount equivalent to the given successive discounts = (100 76)% = 24%...
Read More →Describe the process of urine formation in kidneys.
Question: Describe the process of urine Solution: Mechanism of Urine Formation:It has four components glomerular filtration, selective reabsorption, tubular secretion and concentration. Glomerular Filtration:Blood flows in glomerulus underpressure due to narrowness of efferent arteriole. As a result it undergoes pressure filtration or ultrafiltration. All small volume solutes (e.g., urea, uric acid, amino acids, hormones, glucose, ions, vitamins) and water are filtered out and enter the Bowmans ...
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $e^{x \log x}$ Solution: Let $y=e^{x \log x}$ Taking log both the sides: $\Rightarrow \log y=\log (e)^{x \log x}$ $\Rightarrow \log y=x \log x \log e\left\{\log x^{a}=\operatorname{alog} x\right\}$ $\Rightarrow \log y=x \log x\{\log e=1\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}(\mathrm{x} \log \mathrm{x})}{\mathrm{dx}}$ $\Rightarrow \frac{d(\...
Read More →Solve this
Question: Let $\mathrm{f:} \mathrm{R} \rightarrow \mathrm{R}: \mathrm{f}(\mathrm{x})=\mathrm{x}^{3}+1$ and $\mathrm{g}: \mathrm{R} \rightarrow \mathrm{R}: \mathrm{g}(\mathrm{x})=(\mathrm{x}+1)$. Find: (i) $(f+g)(x)$ (ii) $(f-g)(x)$ (iii) (1/f) (x) (iv) $(f / g)(x)$ Solution: (i) Given: $f(x)=x^{3}+1$ and $g(x)=x+1$ (i) To find: $(f+g)(x)$ $(f+g)(x)=f(x)+g(x)$ $=\left(x^{3}+1\right)+(x+1)$ $=x^{3}+1+x+1$ $=x^{3}+x+2$ Therefore, $(f+g)(x)=x^{3}+x+2$ (ii) To find: $(f-g)(x)$ $(f-g)(x)=f(x)-g(x)$ $=...
Read More →Describe the flow of blood through heart
Question: Describe the flow of blood through heart of human beings. Solution: It is passage of the same blood twice through the heart first on the right side, then on the left side in order to complete one cycle. Double circulation has two components, pulmonary circulation and systemic circulation. Pulmonary Circulation:It is movement of blood from heart to the lungs and back. Deoxygenated blood of the body enters the right auricle, passes into right ventricle which pumps it into pulmonary arch....
Read More →The marked price of a TV is Rs 18500.
Question: The marked price of a TV is Rs 18500. A dealer allows two successive discounts of 20% and 5%. For how much is the TV available? Solution: Marked price of the TV = Rs 18500 First discount $=20 \%$ Now, $20 \%$ of 18500 $=\frac{20}{100} \times 18500$ $=$ Rs 3700 Price after the first discount = Rs (18500 3700)= Rs 14800 Second discount = 5% of 14800 $=\frac{5}{100} \times 14800$ $=740$ Price after the second discount $=(14800-740)$ $=$ Rs 14060 The TV is available for Rs 14060 ....
Read More →Explain the three pathways of breakdown
Question: Explain the three pathways of breakdown (respiration) in living organisms. Solution: (i) Aerobic Respiration:It is a multistep complete oxidative breakdown of respiratory substrate into carbon dioxide and water with the help of oxygen acting as a terminal oxidant. Aerobic respiration is the usual mode of respiration in all higher organisms and most of the lower organisms. The reason is that it yields maximum amount of energy. The energy is stored in some 38 molecules of ATP. Aerobic re...
Read More →Explain the three pathways of breakdown
Question: Explain the three pathways of breakdown (respiration) in living organisms. Solution: (i) Aerobic Respiration:It is a multistep complete oxidative breakdown of respiratory substrate into carbon dioxide and water with the help of oxygen acting as a terminal oxidant. Aerobic respiration is the usual mode of respiration in all higher organisms and most of the lower organisms. The reason is that it yields maximum amount of energy. The energy is stored in some 38 molecules of ATP. Aerobic re...
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $(\sin x)^{\cos x}$ Solution: Let $y=(\sin x)^{\cos x}$ Taking log both the sides: $\Rightarrow \log y=\log (\sin x)^{\cos x}$ $\Rightarrow \log y=\cos x \log \sin x\left\{\log x^{a}=a \log x\right\}$ Differentiating with respect to $\mathrm{x}$ : $\Rightarrow \frac{\mathrm{d}(\log \mathrm{y})}{\mathrm{dx}}=\frac{\mathrm{d}(\cos \mathrm{x} \log \sin \mathrm{x})}{\mathrm{dx}}$ $\Rightarrow \frac{d(\log y)}{d x}=\cos x \times \f...
Read More →How much per cent above the cost price should a shopkeeper mark his goods so that after allowing a discount of 10%
Question: How much per cent above the cost price should a shopkeeper mark his goods so that after allowing a discount of 10% on the marked price, he gains 8%? Solution: Let $R s 100$ be the cost price. Gain required = $8 \%$ Therefore, the selling price is $R s 108$. Let $R s x$ be the marked price. Then, discount $=10 \%$ of $x$ Selling Price = MP discount $\Rightarrow 117=x-\frac{x}{10}$ $\Rightarrow 117=\frac{9 x}{10}$ $\Rightarrow 9 x=1080$ $\Rightarrow x=\frac{1080}{9}$ $\Rightarrow x=120$ ...
Read More →After allowing a discount of 10% on the marked price, a trader still makes a gain of 17%.
Question: After allowing a discount of 10% on the marked price, a trader still makes a gain of 17%. By what per cent is the marked price above the cost price? Solution: Let $R s 100$ be the cost price. Gain required = $17 \%$ $\therefore$ Selling price $=R s 117$ Let the marked price be $R s x$. Then, discount $=10 \%$ of $\mathrm{x}$ $=\frac{10}{100} \times x$ $=\frac{x}{10}$ Selling Price = MP discount $\Rightarrow 117=x-\frac{x}{10}$ $\Rightarrow 117=\frac{9 x}{10}$ $\Rightarrow 9 x=1170$ $\R...
Read More →Explain the mechanism of photosynthesis.
Question: Explain the mechanism of photosynthesis. Solution: Mechanism of Photosynthesis: Photosynthesis is formation of organic food from carbon dioxide and water with the help of sunlight inside chlorophyll containing cells. Oxygen is produced as by-product. Oxygen comes from water. Hydrogen of water is used to reduce carbon dioxide to form carbohydrate. Actually, photosynthesis occurs in two steps, photochemical and biochemical.1.Photochemical Phase (Light or Hill Reaction): The reactions of ...
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $(\log x)^{\cos x}$ Solution: Let $y=(\log x)^{\cos x}$ Taking log both the sides: $\Rightarrow \log y=\log (\log x)^{\cos x}$ $\Rightarrow \log y=\cos x \log \log x\left\{\log x^{a}=\operatorname{alog} x\right\}$ Differentiating with respect to $x$ $\Rightarrow \frac{d(\log y)}{d x}=\frac{d(\cos x \log \log x)}{d x}$ $\Rightarrow \frac{\mathrm{d}(\log y)}{d x}=\cos x \times \frac{d(\log \log x)}{d x}+\log \log x \times \frac{...
Read More →Prove that
Question: Let $f: R \rightarrow R: f(x)=2 x+5$ and $g: R \rightarrow R: g(x)=x^{2}+x$. Find (i) $(f+g)(x)$ (ii) $(f-g)(x)$ (iii) (fg) (x) (iv) $(f / g)(x)$ Solution: (i) Given: $f(x)=2 x+5$ and $g(x)=x^{2}+x$ (i) To find: $(f+g)(x)$ $(f+g)(x)=f(x)+g(x)$ $=(2 x+5)+\left(x^{2}+x\right)$ $=2 x+5+x^{2}+x$ $=x^{2}+3 x+5$ Therefore, $(f+g)(x)=x^{2}+3 x+5$ (ii) To find: $(f-g)(x)$ $(f-g)(x)=f(x)-g(x)$ $=(2 x+5)-\left(x^{2}+x\right)$ $=2 x+5-x^{2}-x$ $=-x^{2}+x+5$ Therefore, $(f+g)(x)=-x^{2}+x+5$ (iii) ...
Read More →A jeweller allows a discount of 16% to his customers and still gains 20%.
Question: A jeweller allows a discount of 16% to his customers and still gains 20%. Find the marked price of a ring which costs the jeweller Rs 1190. Solution: The cost price of the ring is $R s 1190$. Gain percentage $=20 \%$. $\therefore$ Selling price $=\left\{\frac{(100+\text { gain } \%)}{100} \times C . P\right\}$ $=\left\{\frac{100+20}{100} \times 1190\right\}$ $=\frac{120}{100} \times 1190$ $=$ Rs 1428 Let the marked price be $x$. Discount $=16 \%$ of Rs $x$ $=\frac{16 x}{100}$ SP = MP D...
Read More →Differentiate the following functions with respect to x :
Question: Differentiate the following functions with respect to $x$ : $(\log x)^{x}$ Solution: Let $y=(\log x)^{x}$ Taking log both the sides: $\Rightarrow \log y=\log (\log x)^{x}$ $\Rightarrow \log y=x \log (\log x)\left\{\log x^{a}=\operatorname{alog} x\right\}$ Differentiating with respect to $x$ : $\Rightarrow \frac{\mathrm{d}(\log y)}{\mathrm{dx}}=\frac{\mathrm{d}(\mathrm{x} \log \log \mathrm{x})}{\mathrm{dx}}$ $\Rightarrow \frac{d(\log y)}{d x}=x \times \frac{d(\log \log x)}{d x}+\log \lo...
Read More →Solve this
Question: Let $f: R \rightarrow R: f(x)=x+1$ and $g: R \rightarrow R: g(x)=2 x-3 .$ Find (i) $(f+g)(x)$ (ii) $(f-g)(x)$ (iii) (fg) (x) (iv)(f/g) (x) Solution: (i) Given: $f(x)=x+1$ and $g(x)=2 x-3$ (i) To find: $(f+g)(x)$ $(f+g)(x)=f(x)+g(x)$ $=(x+1)+(2 x-3)$ $=x+1+2 x-3$ $=3 x-2$ Therefore, $(f+g)(x)=3 x-2$ (ii) To find: $(f-g)(x)$ $(f-g)(x)=f(x)-g(x)$ $=(x+1)-(2 x-3)$ $=x+1-2 x+3$ $=4-x$ Therefore $(f-g)(x)=4-x$ (iii) To find: (fg)(x) $(f g)(x)=f(x) \cdot g(x)$ $=(x+1)(2 x-3)$ $=x(2 x)-3(x)+1(...
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