For any two rational numbers a and b,
Question: For any two rational numbersaandb,a5b5is equal to (a) (a b)0 (b) (ab)10 (c) (ab)5 (d) (ab)25 Solution: (c) (axb)5 anxbn= (axb)n Hence, a5xb5= (axb)5...
Read More →Differentiate the following activities on the basis of voluntary (V) or involuntary (IV) muscles.
Question: Differentiate the following activities on the basis of voluntary (V) or involuntary (IV) muscles. (a) Jumping of frog, (b) Pumping of heart (c) Writing with hand (d) Movement of chocolate in your intestine. Solution: $a-V$, $b-I V$, $c-V$, $d-I V .$...
Read More →Differentiate between voluntary and
Question: Differentiate between voluntary and involuntary muscles. Given an example of each type. Solution:...
Read More →For any two non-zero rational numbers a and b,
Question: For any two non-zero rational numbersaand b,a4b4is equal to (a) (ab)1 (b) (ab)0 (c) (ab)4 (d) (ab)8 Solution: (c) (ab)4 This is one of the basic exponential formulae, i.e. $(a \div b)^{n}=a^{n} \div b^{n}$....
Read More →Write true (T) and false (F).
Question: Write true (T) and false (F). (a) Epithelial tissue is protective tissue in animal body. (b) The lining of blood vessels, lung alveoli and kidney tubules are all made up of epithelial tissue. (c) Epithelial cells have a lot of intercellular spaces. (d) Epithelial layer is permeable layer. (e) Epithelial layer does not allow regulation of materials between body and external environment. Solution: $a-T$ $b-T$ $c-F$ $d-T$ $e-F$...
Read More →Write matrix A satisfying
Question: Write matrix A satisfying $A+\left[\begin{array}{rr}2 3 \\ -1 4\end{array}\right]=\left[\begin{array}{rr}3 -6 \\ -3 8\end{array}\right]$. Solution: Given : $A+\left[\begin{array}{cc}2 3 \\ -1 4\end{array}\right]=\left[\begin{array}{cc}3 -6 \\ -3 8\end{array}\right]$ $\Rightarrow A=\left[\begin{array}{cc}3 -6 \\ -3 8\end{array}\right]-\left[\begin{array}{cc}2 3 \\ -1 4\end{array}\right]$ $\Rightarrow A=\left[\begin{array}{cc}3-2 -6-3 \\ -3+1 8-4\end{array}\right]$ $\Rightarrow A=\left[\...
Read More →Solve the following
Question: $\left(\frac{3}{4}\right)^{5} \div\left(\frac{5}{3}\right)^{5}$ is equal to Solution: (a) $\left(\frac{3}{4} \div \frac{5}{3}\right)^{5}$ We have: $\left(\frac{3}{4}\right)^{5} \div\left(\frac{5}{3}\right)^{5}=\left(\frac{3}{4} \div \frac{5}{3}\right)^{5} \quad \cdots a^{n} \div b^{n}=(a \div b)^{n}$...
Read More →Draw and identify different elements of phloem.
Question: Draw and identify different elements of phloem. Solution: The various components are phloem fibres, phloem parenchyma, sieve tubes and companion cells....
Read More →Name the different components of xylem and draw a living component.
Question: Name the different components of xylem and draw a living component. Solution: Xylem is made of four components - tracheids, vessels (tracheae), xylem fibres and xylem parenchyma. Only xylem parenchyma is the living component....
Read More →Solve the following
Question: $\left(\frac{2}{3}\right)^{-5} \times\left(\frac{5}{7}\right)^{-5}$ is equal to (a) $\left(\frac{2}{3} \times \frac{5}{7}\right)^{-10}$ (b) $\left(\frac{2}{3} \times \frac{5}{7}\right)^{-5}$ (c) $\left(\frac{2}{3} \times \frac{5}{7}\right)^{25}$ (d) $\left(\frac{2}{3} \times \frac{5}{7}\right)^{-25}$ Solution: (b) $\left(\frac{2}{3} \times \frac{5}{7}\right)^{-5}$ We have: $\left(\frac{2}{3}\right)^{-5} \times\left(\frac{5}{7}\right)^{-5}=\left(\frac{2}{3} \times \frac{5}{7}\right)^{-5...
Read More →If a potted plant is covered with a glass jar,
Question: If a potted plant is covered with a glass jar, water vapours appear on the wall of galss jar. Explan why? Solution: Plants lose water vapours in transpiration from their leaves and young stems. When a potted plant is placed inside a glass jar, the water vapours cannot escape but remain inside. The wall of the glass jar being cool, water vaours condense there....
Read More →Solve this
Question: If $A=\left[a_{i j}\right]$ is a $2 \times 2$ matrix such that $a_{i j}=i+2 j$, write $A .$ Solution: Here, $a_{i j}=i+2 j, 1 \leq i \leq 2$ and $1 \leq j \leq 2$ $\therefore a_{11}=1+2(1)=3, a_{12}=1+2(2)=1+4=5$ $\Rightarrow a_{21}=2+2(1)=4$ and $a_{22}=2+2(2)=2+4=6$ $\therefore A=\left[\begin{array}{ll}a_{11} a_{12} \\ a_{21} a_{22}\end{array}\right]=\left[\begin{array}{ll}3 5 \\ 4 6\end{array}\right]$...
Read More →Solve the following
Question: $\left(\frac{-3}{2}\right)^{-1}$ is equal to (a) $\frac{2}{3}$ (b) $-\frac{2}{3}$ (c) $\frac{3}{2}$ (d) none of these Solution: (b) $-\frac{2}{3}$ We have: $\left(\frac{-3}{2}\right)^{-1}=\frac{1}{(-3) / 2} \quad---\left(a^{-1}=1 / a\right)$ $=\frac{2}{-3}$...
Read More →Malch the column A witli column B.
Question: Malch the column A witli column B. Solution: $a-i$, $b-i i$, $c-i v$, $d-i i i$, $e-v .$...
Read More →Match the items of columns $A$ and $B$.
Question: Match the items of columns $A$ and $B$. Solution: $a-v$, $b-i v$, $c-i i i$, $d-i$, $e-i i$, $f-v i .$...
Read More →Solve this
Question: If $\left[\begin{array}{ll}x 2\end{array}\right]\left[\begin{array}{l}3 \\ 4\end{array}\right]=2$, find $x$ Solution: Given : $\left[\begin{array}{ll}x 2\end{array}\right]\left[\begin{array}{l}3 \\ 4\end{array}\right]=2$ $\Rightarrow 3 x+8=2$ $\Rightarrow 3 x=2-8$ $\Rightarrow 3 x=-6$ $\Rightarrow x=\frac{-6}{3}$ $\Rightarrow x=-2$...
Read More →Animals of colder region and fishes of cold water
Question: Animals of colder region and fishes of cold water have thicker layer of subcutaneous fat. Describe why? Solution: Subcutaneous fat functions as insulating layer that prevents heat loss from the body in colder environment. Therefore, animals of colder areas and fishes of colder water possess thicker layer of subcutaneous fat. Fat also functions as reserve food during periods of scarcity....
Read More →Solve the following equations
Question: If $A=\left[\begin{array}{rr}-3 0 \\ 0 -3\end{array}\right]$, find $A^{4}$ Solution: Here, $A^{2}=A A$ $\Rightarrow A^{2}=\left[\begin{array}{cc}-3 0 \\ 0 -3\end{array}\right]\left[\begin{array}{cc}-3 0 \\ 0 -3\end{array}\right]$ $\Rightarrow A^{2}=\left[\begin{array}{ll}9+0 0+0 \\ 0+0 0+9\end{array}\right]$ $\Rightarrow A^{2}=\left[\begin{array}{ll}9 0 \\ 0 9\end{array}\right]$ Now, $A^{4}=A^{2} A^{2}$ $\Rightarrow A^{4}=\left[\begin{array}{ll}9 0 \\ 0 9\end{array}\right]\left[\begin{...
Read More →Solve the following
Question: $\left(\frac{1}{5}\right)^{0}$ is equal to (a) 0 (b) $\frac{1}{5}$ (c) 1 (d) 5 Solution: (c) 1 We have: $\left(\frac{1}{5}\right)^{0}=1$ --- (a0= 1, for every non-zero rational numbera.)...
Read More →Solve the following
Question: $\left\{\left(\frac{1}{3}\right)^{2}\right\}^{4}$ is equal to (a) $\left(\frac{1}{3}\right)^{6}$ (b) $\left(\frac{1}{3}\right)^{8}$ (c) $\left(\frac{1}{3}\right)^{24}$ (d) $\left(\frac{1}{3}\right)^{16}$ Solution: (b) (1/3)8 We have: $\left(\left(\frac{1}{3}\right)^{2}\right)^{4}=\left(\frac{1}{3}\right)^{2 \times 4} \quad \ldots\left(\left(a^{m}\right)^{n}=a^{m \times n}\right)$ $=\left(\frac{1}{3}\right)^{8}$...
Read More →Without using trigonometric tables, prove that:
Question: Without using trigonometric tables, prove that:(i) sin212 + sin278 = 1(ii) sec229 cot261 = 1(iii) tan256 cot234 = 0(iv) cos257 sin233 = 0(v) sec250 cot240 = 1(vi) cosec272 tan218 = 1 Solution: (i) To prove: sin212 + sin2 78 = 1 $\sin ^{2} 12^{\circ}+\sin ^{2} 78^{\circ}$ $=\left(\sin \left(90^{\circ}-78^{\circ}\right)\right)^{2}+\sin ^{2} 78^{\circ}$ $=\cos ^{2} 78^{\circ}+\sin ^{2} 78^{\circ} \quad\left(\because \sin \left(90^{\circ}-\theta\right)=\cos \theta\right)$ $=1 \quad$ (using...
Read More →Solve this
Question: If $A=\left[\begin{array}{rrr}-1 0 0 \\ 0 -1 0 \\ 0 0 -1\end{array}\right]$, find $A^{3}$ Solution: Here, $A^{2}=A A$ $\Rightarrow A^{2}=\left[\begin{array}{ccc}-1 0 0 \\ 0 -1 0 \\ 0 0 -1\end{array}\right]\left[\begin{array}{ccc}-1 0 0 \\ 0 -1 0 \\ 0 0 -1\end{array}\right]$ $\Rightarrow A^{2}=\left[\begin{array}{cc}1+0+0 0+0+0 0+0+0 \\ 0+0+0 0+1+0 0+0+0 \\ 0+0+0 0+0+0 0+0+1\end{array}\right]$ $\Rightarrow A^{2}=\left[\begin{array}{lll}1 0 0 \\ 0 1 0 \\ 0 0 1\end{array}\right]$ Now, $A^...
Read More →Draw a neat diagram of plant cell and label any
Question: Draw a neat diagram of plant cell and label any three parts which differentiate it from animal cell. Solution: Show chloroplast, large vacuole and cell wall. The three do not occur in the animal cell....
Read More →Solve the following
Question: $\left(\frac{-2}{5}\right)^{7} \div\left(\frac{-2}{5}\right)^{5}$ is equal to (a) $\frac{4}{25}$ (b) $\frac{-4}{25}$ (c) $\left(\frac{-2}{5}\right)^{12}$ (d) $\frac{25}{4}$ Solution: (a) 4/25 We have: $\left(\frac{-2}{5}\right)^{7} \div\left(\frac{-2}{5}\right)^{5}=\left(\frac{-2}{5}\right)^{7-5}$ $=\left(\frac{-2}{5}\right)^{2}$ $=\frac{(-2)^{2}}{5^{2}}$ $=\frac{4}{25}$...
Read More →In brief, state what happens when
Question: In brief, state what happens when 1. Dry apricots are left for some time in pure water and later transferred to sugar solution. 2. A red blood cell is kept in concentrated salt solution. 3. The plasma membrane of a cell breaks down. 4. Rheo leaves are boiled in water first and then drop of sugar syrup is put on it. 5. Golgi apparatus is removed from the cell. Solution: 1. When placed in pure water, dry apricots swell up the due to endosmosis. On being transferred to sugar solution, the...
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