Which of the following gives a reversible operation?
Question: Which of the following gives a reversible operation?Correct Option: , 4 Solution: (4) A logic gate is reversible if we can recover input data from the output. Hence NOT gate....
Read More →Write the equations for the preparation of 1−iodobutane from
Question: Write the equations for the preparation of 1iodobutane from (i)1-butanol (ii)1-chlorobutane (iii)but-1-ene. Solution: (i) (ii) (iii)...
Read More →A cylindrical vessel with internal diameter 10 cm
Question: A cylindrical vessel with internal diameter 10 cm and height 10.5 cm is full of water. A solid cone of base diameter 7 cm and height 6 cm is completely immersed in water. Find the value of water (i) displaced out of the cylinder (ii) left in the cylinder. (Take 22/7) Solution: We have a cylindrical vessel in which a cone is inserted. We have, Radius of the cylinder $\left(r_{1}\right)=5 \mathrm{~cm}$ Radius of cone $\left(r_{2}\right)=3.5 \mathrm{~cm}$ Height of cylinder $(h)=10.5 \mat...
Read More →Write the isomers of the compound having formula
Question: Write the isomers of the compound having formula C4H9Br. Solution: There are four isomers of the compound having the formula C4H9Br. These isomers are given below. (a) 1Bromobutane (b) 2Bromobutane (c) 1Bromo2methylpropane (d) 2Bromo2methylpropane...
Read More →Solve the following
Question: A hydrocarbon C5H10does not react with chlorine in dark but gives a single monochloro compound C5H9Cl in bright sunlight. Identify the hydrocarbon. Solution: A hydrocarbon with the molecular formula, C5H10belongs to the group with a general molecular formula CnH2n. Therefore, it may either be an alkene or a cycloalkane. Since hydrocarbon does not react with chlorine in the dark, it cannot be an alkene. Thus, it should be a cycloalkane. Further, the hydrocarbon gives a single monochloro...
Read More →In ∆ABC, DE ∥ BC so that AD = (7x − 4) cm, AE = (5x − 2) cm, DB
Question: In ∆ABC, DE∥BCso thatAD= (7x 4) cm,AE= (5x 2) cm,DB= (3x+ 4) cm andEC= 3xcm. Then, we have: (a)x= 3(b)x= 5(c)x= 4(d)x= 2.5 Solution: (c)x= 4 It is given that $D E \| B C$. Applying Thales' theorem, we get: $\frac{A D}{B D}=\frac{A E}{E C}$ $\Rightarrow \frac{7 x-4}{3 x+4}=\frac{5 x-2}{3 x}$ $\Rightarrow 3 x(7 x-4)=(5 x-2)(3 x+4)$ $\Rightarrow 21 x^{2}-12 x=15 x^{2}+20 x-6 x-8$ $\Rightarrow 21 x^{2}-12 x=15 x^{2}+14 x-8$ $\Rightarrow 21 x^{2}-12 x-15 x^{2}-14 x+8=0$ $\Rightarrow 6 x^{2}...
Read More →The output characteristics of a transistor is shown in the figure.
Question: The output characteristics of a transistor is shown in the figure. When $\mathrm{V}_{\mathrm{CE}}$ is $10 \mathrm{~V}$ and $\mathrm{I}_{\mathrm{C}}=4.0 \mathrm{~mA}$, then value of $\beta_{\mathrm{ac}}$ is_______ Solution: (150) At $V_{C E}=10 \mathrm{~V}$ and $I_{C}=4 \mathrm{~mA}$ Change in base current, $\Delta I_{B}=(30-20)=10 \mu \mathrm{A}$ Change in collector current, $\Delta I_{C}=(4.5-3)=1.5 \mathrm{~mA}$ $\beta=\left(\frac{\Delta I_{C}}{\Delta I_{B}}\right)=\frac{1.5 \mathrm{...
Read More →A solid consisting of a right circular cone of height 120 cm
Question: A solid consisting of a right circular cone of height 120 cm and radius 60 cm standing on a hemisphere of radius 60 cm is placed upright in a right circular cylinder full of water such that it touches the bottoms. Find the volume of water left in the cylinder, if the radius of the cylinder is 60 cm and its height is 180 cm. Solution: We have to find the remaining volume of water left in the cylinder when the solid is inserted into it. The solid is a hemisphere surmounted by a cone. Rad...
Read More →Which one of the following has the highest dipole moment?
Question: Which one of the following has the highest dipole moment? (i)CH2Cl2 (ii)CHCl3 (iii)CCl4 Solution: (i) Dichlormethane (CH2Cl2) = 1.60D (ii) Chloroform (CHCl3) = 1.08D (iii) Carbon tetrachloride (CCl4) = 0D CCl4is a symmetrical molecule. Therefore, the dipole moments of all four CCl bonds cancel each other. Hence, its resultant dipole moment is zero. As shown in the above figure, in CHCl3, the resultant of dipole moments of two CCl bonds is opposed by the resultant of dipole moments of o...
Read More →Which one of the following has the highest dipole moment?
Question: Which one of the following has the highest dipole moment? (i)CH2Cl2 (ii)CHCl3 (iii)CCl4 Solution: (i) Dichlormethane (CH2Cl2) = 1.60D (ii) Chloroform (CHCl3) = 1.08D (iii) Carbon tetrachloride (CCl4) = 0D CCl4is a symmetrical molecule. Therefore, the dipole moments of all four CCl bonds cancel each other. Hence, its resultant dipole moment is zero. As shown in the above figure, in CHCl3, the resultant of dipole moments of two CCl bonds is opposed by the resultant of dipole moments of o...
Read More →Write the structures of the following organic halogen compounds.
Question: Write the structures of the following organic halogen compounds. (i)2-Chloro-3-methylpentane (ii)p-Bromochlorobenzene (iii)1-Chloro-4-ethylcyclohexane (iv)2-(2-Chlorophenyl)-1-iodooctane (v)Perfluorobenzene (vi)4-tert-Butyl-3-iodoheptane (vii)1-Bromo-4-sec-butyl-2-methylbenzene (viii)1,4-Dibromobut-2-ene Solution: (i) 2-Chloro-3-methylpentane (ii) p-Bromochlorobenzene (iii) 1-Chloro-4-ethylcyclohexane (iv) 2-(2-Chlorophenyl)-1-iodooctane (v) Perfluorobenzene (vi) 4-Tert-Butyl-3-iodohep...
Read More →A solid toy is in the form of a hemisphere surmounted
Question: A solid toy is in the form of a hemisphere surmounted by a right circular cone. height of the cone is 2 cm and the diameter of the base is 4 cm. If a right circular cylinder circumscribes the toy, find how much more space it will cover. Solution: We have to find the remaining volume of the cylinder when the toy is inserted into it. The toy is a hemisphere surmounted by a cone. Radius of cone, cylinder and hemisphere $(r)=2 \mathrm{~cm}$ Height of $\operatorname{cone}(l)=2 \mathrm{~cm}$...
Read More →Identify the correct output signal Y
Question: Identify the correct output signal $\mathrm{Y}$ in the given combination of gates (as shown) for the given inputs $\mathrm{A}$ and $\mathrm{B}$. Correct Option: 1 Solution: (1) Boolean expression, $y=\overline{\bar{A} \cdot \bar{B}}=\overline{\bar{A}}+\overline{\bar{B}}=A+B$ Truth table :...
Read More →Give the IUPAC names of the following compounds:
Question: Give the IUPAC names of the following compounds: (i)CH3CH(Cl)CH(Br)CH3 (ii)CHF2CBrClF (iii)ClCH2CCCH2Br (iv)(CCl3)3CCl (v)CH3C(p-ClC6H4)2CH(Br)CH3 (vi)(CH3)3CCH=CClC6H4I-p Solution: (i) 2Bromo3chlorobutane (ii) 1Bromo1chloro1, 2, 2trifluoroethane (iii) 1Bromo4chlorobut2yne (iv) 2(Trichloromethyl)1,1,1,2,3,3,3heptachloropropane (v) 2Bromo3, 3bis(4chlorophenyl) butane (vi) 1chloro1(4iodophenyl)3, 3dimethylbut1ene...
Read More →A solid iron pole having cylindrical portion 110 cm
Question: A solid iron pole having cylindrical portion 110 cm high and of base diameter 12 cm is surmounted by a cone 9 cm high. Find the mass of the pole, given that the mass of 1 cm3of iron is 8 gm. Solution: We have to find the mass of a pole having a cylindrical base surmounted by a cone. Radius of cone and cylinder $(r)=6 \mathrm{~cm}$ Height of cylinder $(h)=110 \mathrm{~cm}$ Height of cone $(l)=9 \mathrm{~cm}$ So volume of the pole is, $=\pi r^{2} h+\frac{1}{3} \pi r^{2} l$ $=\pi r^{2}\le...
Read More →Name the following halides according to IUPAC system and classify them as alkyl,
Question: Name the following halides according to IUPAC system and classify them as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halides: (i)(CH3)2CHCH(Cl)CH3 (ii)CH3CH2CH(CH3)CH(C2H5)Cl (iii)CH3CH2C(CH3)2CH2I (iv)(CH3)3CCH2CH(Br)C6H5 (v)CH3CH(CH3)CH(Br)CH3 (vi)CH3C(C2H5)2CH2Br (vii)CH3C(Cl)(C2H5)CH2CH3 (viii)CH3CH=C(Cl)CH2CH(CH3)2 (ix)CH3CH=CHC(Br)(CH3)2 (x)p-ClC6H4CH2CH(CH3)2 (xi)m-ClCH2C6H4CH2C(CH3)3 (xii)o-Br-C6H4CH(CH3)CH2CH3 Solution: (i) 2Chloro3methylbutane (Seconda...
Read More →A right circular cylinder having diameter 12 cm and height 15 cm
Question: A right circular cylinder having diameter 12 cm and height 15 cm is full ice-cream. The ice-cream is to be filled in cones of height 12 cm and diameter 6 cm having a hemispherical shape on the top. Find the number of such cones which can be filled with ice-cream. Solution: We have to find the number of cones which can be filled using the ice cream in the cylindrical vessel. Radius of the cylinder $\left(r_{1}\right)=6 \mathrm{~cm}$ Height of cylinder $(h)=15 \mathrm{~cm}$ Radius of con...
Read More →In ∆ABC, DE is drawn parallel to BC, cutting AB and AC at D and E, respectively, such that AB = 7.2 cm
Question: In ∆ABC,DEis drawn parallel toBC, cuttingABandACatDandE,respectively, such thatAB= 7.2 cm,AC= 6.4 cm andAD= 4.5 cm. FindAE. (a) 5.4 cm(b) 4 cm(c) 3.6 cm(d) 3.2 cm Solution: (b) 4 cmIt is given thatDE∥BC.Applying basic proportionality theorem, we get: $\frac{A D}{A B}=\frac{A E}{A C}$ $\Rightarrow \frac{4.5}{7.2}=\frac{A E}{6.4}$ $\Rightarrow A E=\frac{4.5 \times 6.4}{7.2}=4 \mathrm{~cm}$...
Read More →Identify A, B, C, D, E, R
Question: Identify A, B, C, D, E, R and R1in the following: Solution: Since D of D2O gets attached to the carbon atom to which MgBr is attached, C is Therefore, the compound R Br is When an alkyl halide is treated with Na in the presence of ether, a hydrocarbon containing double the number of carbon atoms as present in the original halide is obtained as product. This is known as Wurtz reaction. Therefore, the halide, R1X, is Therefore, compound D is And, compound E is...
Read More →The difference between outside and inside surface
Question: The difference between outside and inside surface areas of cylindrical metallic pipe 14 cm long is 44 m2. If the pipe is made of 99 cm3of metal, find the outer and inner radii of the pipe. Solution: We have to find the outer and inner radius of a hollow pipe. Radius of inner pipe be $\left(r_{1}\right)$ Radius of outer cylinder be $\left(r_{2}\right)$ Length of the cylinder $(h)=14 \mathrm{~cm}$ Difference between the outer and the inner surface area is $44 \mathrm{~cm}^{2}$ So, $2 \pi...
Read More →In ∆ABC, DE ∥ BC so that AD = 2.4 cm, AE = 3.2 cm
Question: In ∆ABC, DE∥BCso thatAD= 2.4 cm,AE= 3.2 cm andEC= 4.8 cm. Then,AB= ? (a) 3.6 cm(b) 6 cm(c) 6.4 cm(d) 7.2 cm Solution: (b) 6 cmIt is given that DE∥BC.Applying basic proportionality theorem, we have: $\frac{A D}{B D}=\frac{A E}{E C}$ $\Rightarrow \frac{2.4}{B D}=\frac{3.2}{4.8}$ $\Rightarrow B D=\frac{2.4 \times 4.8}{3.2}=3.6 \mathrm{~cm}$ Therefore, AB = AD + BD = 2.4 + 3.6 = 6 cm...
Read More →Two Zener diodes ( A and B ) having breakdown voltages
Question: Two Zener diodes ( $A$ and $B$ ) having breakdown voltages of $6 \mathrm{~V}$ and $4 \mathrm{~V}$ respectively, are connected as shown in the circuit below. The output voltage $V_{0}$ variation with input voltage linearly increasing with time, is given by: $\left(V_{\text {input }}=0 \mathrm{~V}\right.$ at $\left.t=0\right)$ (figures are qualitative) Correct Option: , 3 Solution: (3) Till input voltage reaches $4 \mathrm{~V}$. No zener is in breakdown region so $V_{0}=V_{i}$. Then now ...
Read More →Two Zener diodes ( A and B ) having breakdown voltages
Question: Two Zener diodes ( $A$ and $B$ ) having breakdown voltages of $6 \mathrm{~V}$ and $4 \mathrm{~V}$ respectively, are connected as shown in the circuit below. The output voltage $V_{0}$ variation with input voltage linearly increasing with time, is given by: $\left(V_{\text {input }}=0 \mathrm{~V}\right.$ at $\left.t=0\right)$ (figures are qualitative) Correct Option: , 3 Solution: (3) Till input voltage reaches $4 \mathrm{~V}$. No zener is in breakdown region so $V_{0}=V_{i}$. Then now ...
Read More →In ∆ABC, it is given that
Question: In $\triangle A B C$, it is given that $\frac{A B}{A C}=\frac{B D}{D C}$. If $\angle B=70^{\circ}$ and $\angle C=50^{\circ}$, then $\angle B A D=$ ? (a) 30(b) 40(c) 45(d) 50 Solution: (a) 30We have: $\frac{A B}{A C}=\frac{B D}{D C}$ Applying angle bisector theorem, we can conclude that $A D$ bisects $\angle A$. In $\triangle A B C$, $\angle A+\angle B+\angle C=180^{\circ}$ $\Rightarrow \angle A=180-\angle B-\angle C$ $\Rightarrow \angle A=180-70-50=60^{\circ}$ $\because \angle B A D=\a...
Read More →A toy is in the form of a cone of radius 3.5 cm
Question: A toy is in the form of a cone of radius 3.5 cm mounted on a hemisphere of same radius. The total height of the toy is 15.5 cm. Find the total surface area of the toy. Solution: We have to find the total surface area of a toy which is a cone surmounted on a hemisphere. Radius of hemisphere and the base of the cone $(r)=3.5 \mathrm{~cm}$ Height of the cone, h = 15.5 3.5 = 12 cm slant height $(l)=\sqrt{\mathrm{h}^{2}+\mathrm{r}^{2}}$ $=\sqrt{12^{2}+3.5^{2}}$ $=\sqrt{156.25}$ $=12.5 \math...
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