Is it necessary for a transmitting antenna to be at the same height as that of the receiving antenna for line-of-sight communication?
Question: Is it necessary for a transmitting antenna to be at the same heightas that of the receiving antenna for line-of-sight communication? A TV transmitting antenna is 81m tall. How much service area can it cover if the receiving antenna is at the ground level? Solution: Line-of-sight communication means that there is no physical obstruction between the transmitter and the receiver. In such communications it is not necessary for the transmitting and receiving antennas to be at the same heigh...
Read More →Digital signals
Question: Digital signals (i) Do not provide a continuous set of values, (ii) Represent values as discrete steps, (iii) Can utilize binary system, and (iv) Can utilize decimal as well as binary systems. Which of the above statements are true? (a) (i) and (ii) only (b) (ii) and (iii) only (c) (i), (ii) and (iii) but not (iv) (d) All of (i), (ii), (iii) and (iv). Solution: (c) Answer: A digital signal usesthe binary (0 and 1) system for transferring message signals. Such a system cannot utilise th...
Read More →Examine the continuity of f, where f is defined by
Question: Examine the continuity off, wherefis defined by $f(x)= \begin{cases}\sin x-\cos x, \text { if } x \neq 0 \\ -1 \text { if } x=0\end{cases}$ Solution: The given function $f$ is $f(x)= \begin{cases}\sin x-\cos x, \text { if } x \neq 0 \\ -1 \text { if } x=0\end{cases}$ It isevident thatfis defined at all points of the real line. Letcbe a real number. Case I: If $c \neq 0$, then $f(c)=\sin c-\cos c$ $\lim _{x \rightarrow c} f(x)=\lim _{x \rightarrow c}(\sin x-\cos x)=\sin c-\cos c$ $\ther...
Read More →Draw a labeled diagram of sperm.
Question: Draw a labeled diagram of sperm. Solution:...
Read More →Frequencies in the UHF range normally propagate by means of:
Question: Frequencies in the UHF range normally propagate by means of: (a)Ground waves. (b)Sky waves. (c)Surface waves. (d)Space waves. Solution: (d) Answer: Space waves Owing to its high frequency, an ultra high frequency (UHF)wave can neither travel along the trajectory of the ground nor can it get reflected by the ionosphere. The signals having UHF are propagated through line-of-sight communication, which is nothing but space wave propagation....
Read More →Which of the following frequencies will be suitable for beyond-the-horizon communication using sky waves?
Question: Which of the following frequencies will be suitable for beyond-the-horizon communication using sky waves? (a)10 kHz (b)10 MHz (c)1 GHz (d)1000 GHz Solution: (b) Answer: 10 MHz Forbeyond-the-horizon communication, it is necessary for the signal waves to travel a large distance. 10 KHz signals cannot be radiated efficiently because of the antenna size. The high energy signal waves (1GHz 1000 GHz) penetrate the ionosphere. 10 MHz frequencies get reflected easily from the ionosphere. Hence...
Read More →Define spermiogenesis and spermiation.
Question: Define spermiogenesis and spermiation. Solution: Spermiogenesis:It is the process of transforming spermatids into matured spermatozoa or sperms. Spermiation:It is the process when mature spermatozoa are released from the sertoli cells into the lumen of seminiferous tubules....
Read More →The vertices of ΔPQR are P (2, 1), Q (–2, 3) and R (4, 5).
Question: The vertices of $\triangle P Q R$ are $P(2,1), Q(-2,3)$ and $R(4,5)$. Find equation of the median through the vertex $R$. Solution: It is given that the vertices of $\triangle \mathrm{PQR}$ are $\mathrm{P}(2,1), \mathrm{Q}(-2,3)$, and $\mathrm{R}(4,5)$. Let RL be the median through vertex R. Accordingly, L is the mid-point of PQ. By mid-point formula, the coordinates of point $L$ are given by $\left(\frac{2-2}{2}, \frac{1+3}{2}\right)=(0,2)$ It is known that the equation of the line pa...
Read More →Name the hormones involved in regulation of spermatogenesis.
Question: Name the hormones involved in regulation of spermatogenesis. Solution: Follicle-stimulating hormones (FSH) and luteinizing hormones (LH) are secreted by gonadotropin releasing hormones from the hypothalamus .These hormones are involved in the regulation of the process of spermatogenesis. FSH acts on sertoli cells, whereas LH acts on leydig cells of the testis and stimulates the process of spermatogenesis....
Read More →Determine if f defined by
Question: Determine iffdefined by $f(x)= \begin{cases}x^{2} \sin \frac{1}{x}, \text { if } x \neq 0 \\ 0, \text { if } x=0\end{cases}$ is a continuous function? Solution: The given function $f$ is $f(x)= \begin{cases}x^{2} \sin \frac{1}{x}, \text { if } x \neq 0 \\ 0, \text { if } x=0\end{cases}$ It isevident thatfis defined at all points of the real line. Letcbe a real number. Case I: If $c \neq 0$, then $f(c)=c^{2} \sin \frac{1}{c}$ $\lim _{x \rightarrow c} f(x)=\lim _{x \rightarrow c}\left(x^...
Read More →What is spermatogenesis?
Question: What is spermatogenesis? Briefly describe the process of spermatogenesis. Solution: Spermatogenesis is the process of the production of sperms from the immature germ cells in males. It takes place in seminiferous tubules present inside the testes. During spermatogenesis, a diploid spermatogonium (male germ cell) increases its size to form a diploid primary spermatocyte. This diploid primary spermatocyte undergoes first meiotic division (meiosis I), which is a reductional division to fo...
Read More →Find the equation of the line which is at a perpendicular distance of 5 units
Question: Find the equation of the line which is at a perpendicular distance of 5 unitsfrom the origin and the angle made by the perpendicular with the positivex-axis is$30^{\circ}$ Solution: If $p$ is the length of the normal from the origin to a line and $\omega$ is the angle made by the normal with the positive direction of the $x$-axis, then the equation of the line is given by $x \cos \omega+y \sin \omega=p$. Here, $p=5$ units and $\omega=30^{\circ}$ Thus, the required equation of the given...
Read More →Describe the structure of a seminiferous tubule.
Question: Describe the structure of a seminiferous tubule. Solution: The production of sperms in the testes takes place in a highly coiled structure called the seminiferous tubules. These tubules are located in the testicular lobules. Each seminiferous tubule is lined by germinal epithelium. It is lined on its inner side by two types of cells namely spermatogonia and sertoli cells respectively. Spermatogonia are male germ cells which produce primary spermatocytes by meiotic divisions. Primary sp...
Read More →Write the truth table for the circuits given in Fig. 14.48 consisting of NOR gates only.
Question: Write the truth table for the circuits given in Fig. 14.48 consisting of NOR gates only. Identify the logic operations (OR, AND, NOT) performed by the two circuits. Solution: (a) $A$ acts as the two inputs of the NOR gate and $Y$ is the output, as shown in the following figure. Hence, the output of the circuit is $\overline{A+A}$. Output, $Y=\overline{A+A}=\bar{A}$ The truth table for the same is given as: This is the truth table of a NOT gate. Hence, this circuit functions as a NOT ga...
Read More →Write two major functions each of testis and ovary.
Question: Write two major functions each of testis and ovary. Solution: Functions of the Testis: (a)They produce male gametes called spermatozoa by the process of spermatogenesis. (b)The leydig cells of the seminiferous tubules secrete the male sex hormone called testosterone. Testosterone aids the development of secondary sex characteristics in males. Functions of the ovary: (a)They produce female gametes called ova by the process of oogenesis. (b)The growing Graffian follicles secrete the fema...
Read More →Find the points of discontinuity of f, where
Question: Find the points of discontinuity off, where $f(x)=\left\{\begin{array}{l}\frac{\sin x}{x}, \text { if } x0 \\ x+1, \text { if } x \geq 0\end{array}\right.$ Solution: The given function $f$ is $f(x)= \begin{cases}\frac{\sin x}{x}, \text { if } x0 \\ x+1, \text { if } x \geq 0\end{cases}$ It isevident thatfis defined at all points of the real line. Letcbe a real number. Case I: If $c0$, then $f(c)=\frac{\sin c}{c}$ and $\lim _{x \rightarrow c} f(x)=\lim _{x \rightarrow c}\left(\frac{\sin...
Read More →Draw a labeled diagram of female reproductive system.
Question: Draw a labeled diagram of female reproductive system. Solution:...
Read More →Write the truth table for circuit given in Fig.
Question: Write the truth table for circuit given in Fig. 14.47 below consisting of NOR gates and identify the logic operation (OR, AND, NOT) which this circuit is performing. (Hint: A = 0, B = 1 then A and B inputs of second NOR gate will be 0 and hence Y=1. Similarly work out the values of Y for other combinations of A and B. Compare with the truth table of OR, AND, NOT gates and find the correct one.) Solution: $A$ and $B$ are the inputs of the given circuit. The output of the first NOR gate ...
Read More →Draw a labeled diagram of male reproductive system.
Question: Draw a labeled diagram of male reproductive system. Solution:...
Read More →Fill in the blanks:
Question: Fill in the blanks: (a)Humans reproduce __________. (asexually/sexually) (b)Humans are__________. (oviparous/viviparous/ovoviviparous) (c)Fertilization is __________ in humans. (external/internal) (d)Male and female gametes are __________. (diploid/haploid) (e)Zygote is __________. (diploid/haploid) (f)The process of release of the ovum from a mature follicle is called__________. (g)Ovulation is induced by a hormone called the __________. (h)The fusion of the male and the female gamete...
Read More →You are given two circuits as shown in Fig. 14.46, which consist of NAND gates.
Question: You are given two circuits as shown in Fig. 14.46, which consist of NAND gates. Identify the logic operation carried out by the two circuits. Solution: In both the given circuits,AandBare the inputs andYis the output. (a) The output of the left NAND gate will be $\overline{A \cdot B}$, as shown in the following figure. Hence, the output of the combination of the two NAND gates is given as: $Y=\overline{(\overline{A \cdot B}) \cdot(\overline{A \cdot B})}=\overline{\overline{A B}}+\overl...
Read More →Find the equation of the line which passes through the points
Question: Find the equation of the line which passes through the points (1, 1) and (2, 4). Solution: It is known that the equation of the line passing through points $\left(x_{1}, y_{1}\right)$ and $\left(x_{2}, y_{2}\right)$ is $y-y_{1}=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\left(x-x_{1}\right)$. Therefore, the equation of the line passing through the points (1, 1) and (2, 4) is $(y-1)=\frac{-4-1}{2+1}(x+1)$ $(y-1)=\frac{-5}{3}(x+1)$ $3(y-1)=-5(x+1)$ $3 y-3=-5 x-5$ i.e., $5 x+3 y+2=0$...
Read More →Write the truth table for a NAND gate connected as given in Fig. 14.45.
Question: Write the truth table for a NAND gate connected as given in Fig. 14.45. Hence identify the exact logic operation carried out by this circuit. Solution: Aacts as the two inputs of the NAND gate andYis the output, as shown in the following figure. Hence, the output can be written as: $Y=\overline{A \cdot A}=\bar{A}+\bar{A}=\bar{A}$ ...(1) The truth table for equation (i) can be drawn as: This circuit functions as a NOT gate. The symbol for this logic circuit is shown as:...
Read More →Find the equation of the line which intersects the y-axis at a distance of 2 units above the origin
Question: Find the equation of the line which intersects the $y$-axis at a distance of 2 units above the origin and makes an angle of $30^{\circ}$ with the positive direction of the $x$ axis. Solution: It is known that if aline with slopemmakesy-interceptc, then the equation of the line is given as y=mx + c Here, $c=2$ and $m=\tan 30^{\circ}=\frac{1}{\sqrt{3}}$. Thus, the required equation of the given line is $y=\frac{1}{\sqrt{3}} x+2$ $y=\frac{x+2 \sqrt{3}}{\sqrt{3}}$ $\sqrt{3} y=x+2 \sqrt{3}$...
Read More →Discuss the continuity of the cosine, cosecant, secant and cotangent functions,
Question: Discuss the continuity of the cosine, cosecant, secant and cotangent functions, Solution: It is known that ifgandhare two continuous functions, then (i) $\frac{h(x)}{g(x)}, g(x) \neq 0$ is continuous (ii) $\frac{1}{g(x)}, g(x) \neq 0$ is continuous (iii) $\frac{1}{h(x)}, h(x) \neq 0$ is continuous It has to be proved first that $g(x)=\sin x$ and $h(x)=\cos x$ are continuous functions. Letg(x) = sinx It is evident thatg(x) = sinxis defined for every real number. Letcbe a real number. Pu...
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