Which of the following is correct?

Atleast three geostationary satellite in the same orbit around the earth can cover the whole part of the earth for microwave communication

A single geostationary satellite can cover the whole part of the earth for microwave communication

The correct Option is "Atleast three geostationary satellites in the same orbit around earths can cover the whole part of the earth for microwave communication"

The first Indian communication satellite is Apple

The satellite communication is not like the line of sight microwave communication.

Which of the following is correct the ploidy level in labelled organs of plant shown in given figure?

Sporophyte - Diploid (2n) Antheridia – Haploid (n) Rhizoids - Haploid (n)

The correct Option is "All of the above"

Which of the following is correct order of increasing size?

The correct Option is "${\rm{B}}{{\rm{r}}^ - } > {{\rm{S}}^{2 - }} > C{{\rm{l}}^ - } > N{{\rm{a}}^ + } > M{{\rm{g}}^{2 + }} > B{{\rm{e}}^{2 + }}$"

${\rm{B}}{{\rm{e}}^{2 + }} > \;M{{\rm{g}}^{2 + }} > {\rm{\;N}}{{\rm{a}}^ + } > {{\rm{S}}^{2 - }} > {\rm{C}}{{\rm{l}}^ - } > {\rm{B}}{{\rm{r}}^ - }$

${{\rm{S}}^{2 - }} > {\rm{\;C}}{{\rm{l}}^ - } > B{{\rm{r}}^ - } > {\rm{N}}{{\rm{a}}^ + } > {\rm{M}}{{\rm{g}}^{2 + }} > {\rm{B}}{{\rm{e}}^{2 + }}$

${\rm{N}}{{\rm{a}}^ + } > {\rm{M}}{{\rm{g}}^{2 + }} > {\rm{B}}{{\rm{e}}^{2 + }} > {\rm{B}}{{\rm{r}}^ - } > {\rm{C}}{{\rm{l}}^ - } > {{\rm{S}}^{2 - }}$

For electron affinity of halogens, which of the following is correct?

The order of electron affinity among the halogens is ${\rm{Cl}} > F > Br > I$

The correct Option is "${\rm{Br\;}} < \;Cl\;$"

Which of the following is correct matched?

Sulphur and phosphorus cycle are sedimentary cycle.

Rhizobium – Free-living nitrogen fixer

The correct Option is "Phosphorus cycle – Sedimentary"

Shorea robusta – Tropical deciduous forest

Which of the following is correct in case of chemical synapses? I. The membranes of the pre and postsynaptic neurons are separated by a gap called synaptic cleft II. Chemicals called neurotransmitters are involved in the transmission of impulses III. Impulse transmission in chemical synapse is faster than that across an electrical synapse IV. Chemical synapses are rare in our system

A nerve impulse is transmitted from one neuron to another through junctions called synapses. A synapse is formed by the membranes of a presynaptic neuron and a postsynaptic neuron, which may or may not be separated by a gap called synaptic cleft There are two types of synapses, i.e., electrical synapses and chemical synapses. At electrical synapses, the membrane of pre- and postsynaptic neurons are in very close proximity. Electrical current can flow directly from one neuron into the other across these synapses Transmission of an impulse across electrical synapses is very similar to impulse conduction along a single axon. Impulse transmission across an electrical synapse is always faster than the across a chemical synapse. Electrical synapses are rare in our system At a chemical synapse, the membranes of the pre- and postsynaptic neurons are separated by fluid-filled space called synaptic cleft. Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses

The correct Option is "I and II"

The nervous tissue forms the nervous system in animals. Which of the following is correct about its origin?

Nervous tissue forms the nervous system in animals. It is ectodermal in origin

The correct Option is "Ectodermal"

Given ${\rm{\vec A}} = 4\hat i + 6\hat j\,and\,{\rm{\vec B}} = 2\hat i + 3\hat j$. Which of the following is correct?

${\rm{\vec A}} \times {\rm{\vec B}} = \left( {4\hat i + 6\hat j{\rm{\;}}} \right) \times \left( {2\hat i + 3\hat j{\rm{\;}}} \right) = 12\left( {\hat i \times \hat j{\rm{\;}}} \right) + 12\left( {\hat j \times \hat i{\rm{\;}}} \right) = 12\left( {\hat i \times \hat j{\rm{\;}}} \right) - 12\left( {\hat i \times \hat j{\rm{\;}}} \right) = 0$ Again, ${\rm{\vec A}}{\rm{.\vec B}} = \left( {4\hat i + 6\hat j{\rm{\;}}} \right).\left( {2\hat j + 3\hat i{\rm{\;}}} \right) = 8 + 18 = 26$ Again, $\frac{{\left| {{\rm{\vec A}}} \right|}}{{\left| {{\rm{\vec B}}} \right|}} = \frac{{\sqrt {16 + 36} }}{{\sqrt {4 + 9} }} \ne \frac{1}{2}$ Again , ${\rm{\vec B}} = \frac{1}{2}{\rm{\;\vec A}}$

The correct Option is "${\rm{\vec A}} \times {\rm{\vec B}} = \vec 0$"

${\rm{\vec A}}{\rm{.\vec B}} = 24$

$\frac{{\left| {{\rm{\vec A}}} \right|}}{{\left| {{\rm{\vec B}}} \right|}} = \frac{1}{2}$

${\rm{\vec A\;}}\,and\,{\rm{\vec B}}$ are anti-parallel

Which of the following is correct for a reaction to be spontaneous?

$\Delta G = \Delta H - T\Delta S\,\,\,For\,\,spon\tan eity\,\,\Delta G = - ve\,\,\Delta S = + ve\,\,\Delta H = - ve$

$\Delta G = + ve,\,\,\Delta H = + ve$

The correct Option is "$\Delta H = - ve,\,\,\Delta S = + ve$"

$\Delta G = + ve,{\mkern 1mu} {\mkern 1mu} \Delta H = - ve$

$\Delta H = + ve,\,\,\Delta S = - ve$

Which of the following is correct for middle lamella of eukaryotic cell?

All the given statements are correct

It is formed as a cell plate during cytokinesis

It is mainly consists of Ca-pectate

It holds different neighbouring cells together

The correct Option is "All of the above"

Gases deviate from ideal gas behaviour at high pressure. Which of the following is correct for non ideality?

A fact for deviations from ideal gas behaviour.

At high pressure, the collision between the gas molecules becomes enormous

At high pressure, the gas molecules move only in one direction

At high pressure, the volume of gas becomes insignificant

The correct Option is "At high pressure, the intermolecular interaction become significant"

Which of the following is correct about Neela Kuranji?

All are correct Strobilanthus kunthiana also called Neela Kuranji in local language. It is found in Kerala, Maharashtra, Tamil Nadu. It reproduce once in 12 yr Last time it was reproduced in Sept-Oct, 2006 and produced blue flower in massive quantity. It attracted tourist because all of the area appeared blue

Last time it was flowered in Sept-Oct.2006

Next time it will have flower in Sept-Oct.2018

It is found in Kerala, Tamil Nadu and Karnataka

The correct Option is "All of the above"

Which of the following is correct? I. Wine and beer are produced without distillation of fermented broth II. Whisky, brandy and rum are produced by distillation of the fermented broth III. Wine and beer are produced by distillation of the fermented broth IV. Whisky, brandy and rum are produced without distillation of the fermented broth Choose the correct option

Wine and beer are produced without distillation of fermented broth Whisky, brandy and rum are produced by distillation of the fermented broth

The correct Option is "I and II"

Which of the following is correct for an ideal gas :

Internal energy of an ideal gas is function of temperature and thus ${\left( {\frac{{\partial E}}{{\partial P}}} \right)_T}$= 0

${\left( {\frac{{\partial E}}{{\partial T}}} \right)_V}$= 0

The correct Option is "${\left( {\frac{{\partial E}}{{\partial P}}} \right)_T}$= 0"

$\;{\left( {\frac{{\partial E}}{{\partial T}}} \right)_P}$= 0

Which of the following is correct about mammalian testes?

Sertoli’s cells, seminiferous tubules and Leydig’s cells, all are present in testes, while Graafian follicles are present in ovary of mammals.

Graafian follicles, sertoli’s cells, Leydig’s cells

Graafian follicles, sertoli’s cells, seminiferous tubules

The correct Option is "Sertoli’s cells, seminiferous tubules, Leydig’s cells"

Graafian follicles, Leydig’s cells, seminiferous tubules

Which of the following is correct?

${\rm{S}}{{\rm{F}}_6}$ does not obey octet rule as in it $S - $ atom has 12 electrons in its valence shell.

The correct Option is "The number of electrons present in the valence shell of $S$ in ${\rm{S}}{{\rm{F}}_6}$is 12."

The rates of ionic reactions are very low.

According to VSEPR theory, ${\rm{SnC}}{{\rm{I}}_2}$ is a linear molecule.

The correct order of ability to form ionic compounds among ${\rm{N}}{{\rm{a}}^ + },{\rm{M}}{{\rm{g}}^{2 + }}$ and ${\rm{A}}{{\rm{l}}^{3 + }}$ is ${\rm{A}}{{\rm{l}}^{3 + }} > M{{\rm{g}}^{2 + }} > N{{\rm{a}}^ + }$.

Which of the following is correct option for free expansion of an ideal gas under adiabatic condition?

The correct Option is "q=0,∆T=0,w=0"

Which of the following is correct?

Alkali metals are electropositive, hence they can reduce ${\rm{C}}{{\rm{O}}_2}$ . $4{\rm{Na}} + {\rm{C}}{{\rm{O}}_2} \to 2{\rm{N}}{{\rm{a}}_2}{\rm{O}} + {\rm{C}}$

In the Castner’s process of sodium extraction, NaCl is used as an electrolyte.

The correct Option is "Sodium reduces ${\rm{C}}{{\rm{O}}_2}$ to carbon."

Mg reacts with cold water and liberate hydrogen gas.

Magnalium is an alloy of Mg and Zn.

Which of the following is correct for the reaction? ${{\rm{N}}_2}\left( {\rm{g}} \right) + 3{{\rm{H}}_2}\left( {\rm{g}} \right)\leftrightharpoons2{\rm{N}}{{\rm{H}}_3}\left( {\rm{g}} \right)$

${{\rm{N}}_2}\left( {\rm{g}} \right) + 3{{\rm{H}}_2}\left( {\rm{g}} \right)\leftrightharpoons2{\rm{N}}{{\rm{H}}_3}\left( {\rm{g}} \right)$ $\Delta n = {n_p} - {n_r}$ $ = 2 - 4$ $ = - 2$ $\therefore {K_p} = {K_c}{\left( {RT} \right)^{ - 2}}$ or ${K_p} = \frac{{{K_c}}}{{{{\left( {RT} \right)}^2}}}$ ${K_p} < {K_c}$

The correct Option is "${K_p} < {K_c}$"

Pressure is required to predict the correlation

For a reaction and equilibrium which of the following is correct?

At chemical equilibrium, rate of forward reaction is equal to the rate of backward reaction.

Concentration of reactant=concentration of product

Concentration of reactant is always greater than product

The correct Option is "Rate of forward reaction=rate of backward reaction"

Which of the following is correct formula of Gammaxane

${C_6}{H_6}C{l_6}$ is called gammaxene.

The correct Option is "${C_6}{H_6}C{l_6}$"

For the combustion reaction at $298\,K$ ${H_2}(g) + \frac{1}{2}{O_2}(g) \to {H_2}O(l)$ which of the following is correct?

$\Delta n = {n_P} - {n_R} = O - \frac{3}{2} = - 1.5$ $\Delta n < O,\Delta H < \Delta U$

The correct Option is "$\Delta H < \Delta E$"

If the lattice constant of this semiconductor is decreased, then which of the following is correct?

If lattice constant of semiconductor is decreased, then ${E_c}\;$ and ${E_v}$ decrease, but ${E_g}$ increases.

All ${E_c},\;\;{E_g},\;\;{E_v}$ increase

${E_c}$ and ${E_v}$ increase, but ${E_g}$ decreases

The correct Option is "${E_c}$ and ${E_v}$ decrease, but ${E_g}$ increases"

All ${E_c},\;\;{E_g},\;\;{E_v}$ decreases

Which of the following is correct?

Zn is placed above Sn in electrochemical series.

Zinc acts as cathode in Daniell cell

In a ${\rm{Li}} - {\rm{Zn}}$ couple, zinc acts as anode

Copper will displace iron in solution

The correct Option is "Zinc displaces tin from its solution"

Which of the following is correct about heavy water?

${{\rm{D}}_2}{\rm{O}}$ had deuterium (heavier isotope of ${\rm{H}}$) and ${\rm{O}}$ (the tighter one ${{{\rm{O}}^{16}}}$).

Water at $4^\circ C$ having maximum density is known as heavy water

It is heavier than water ${\rm{(}}{{\rm{H}}_2}{\rm{O )}}$

The correct Option is "It is formed by the combination of heavier isotope of hydrogen and oxygen"

Which of the following is correct according to adsorption isotherm?

All the option are correct for Freundlich adsorption isotherm at different pressures. $\frac{x}{m} = k{p^1}$ (at low pressure) $\frac{x}{m} = k{p^0}$ (at high pressure) $\frac{x}{m} = k{p^{1/n}}$ (at intermediate pressure)

$\frac{x}{m} \propto {p^{1/n}}$

The correct Option is "All of these"

Which of the following is correct?

Aldehydes are easily oxidised to respective acids.

All aldehydes undergo Cannizzaro’s reaction

Aldehydes are less susceptible to oxidation than ketones

The correct Option is "Aldehydes are more susceptible to oxidation than ketones"

Formaldehyde forms ${\rm{C}}{{\rm{H}}_2}\left( {{\rm{OH}}} \right){\rm{N}}{{\rm{H}}_2}\;with\;{\rm{N}}{{\rm{H}}_3}$

Which of the following is correct?

Calomel is widely used as an antiseptic

The correct Option is "Calomel is used medically as purgative"

Calomel is freely soluble in water

Which of the following is correct for ${\rm{C}}\left( {{\rm{graphite}}} \right) + {{\rm{O}}_2}\left( {{\rm{gas}}} \right) \to {\rm{C}}{{\rm{O}}_2},heat{\rm{ }} = 348\;kJ?$

$\begin{array}{l} C\;graphite + {{\rm{O}}_2}\left( {\rm{g}} \right) \to {\rm{C}}{{\rm{O}}_2};\Delta H = - 348\;kJ\\ 12\;g\;\;\;\;\;\;\;\;\;\;\;\;\;32\;g\;\;\;\;\;\;\;\;44\;g \end{array}$ In the above reaction, heat is evolved and mass of product is equal to mass of reactant.

Mass of product >Mass of reactant

Mass of product < Mass of reactant

The correct Option is "Mass of product = Mass of reactant"

Moment of inertia of a cylinder of mass $M$, length $L$ and radius $R$ about an axis passing through its centre and perpendicular to the axis of the cylinder is $I = M\left[ {\frac{{{R^2}}}{4} + \frac{{{L^2}}}{{12}}} \right]$. If such a cylinder is to be made for a given mass of a material. To have minimum possible moment of inertia, the ratio $L/R$ for cylinder is

Mass of cylinder, $M = \rho \pi {R^2}L\,\,\,\,\,\,\,\,\,\,\,\,\,...(i)$ (Where, $\rho = $ density of material) $ \Rightarrow \,\,L = \frac{M}{{\rho \pi {R^2}}}\,\,\,\,\,\,\,\,\,\,\,\,...(ii)$ Moment of inertia of a Cylinder, $I = M\left( {\frac{{{R^2}}}{4} + \frac{{{L^2}}}{{12}}} \right)$ $ \Rightarrow \,\,\,$ $I = M\left( {\frac{{{R^2}}}{4} + \frac{{{M^2}}}{{12{\rho ^2}{\pi ^2}{R^4}}}} \right)\,\,\,\,\,\,\,\,\,\,\,\,$ [From Eq.(ii)] For moment of inertia to be minimum, $\frac{{dI}}{{dR}} = 0$ $ \Rightarrow \,\,\,\frac{d}{{dR}}\left[ {M\left( {\frac{{{R^2}}}{4} + \frac{{{M^2}}}{{12{\rho ^2}{\pi ^2}{R^4}}}} \right)} \right] = 0\,$ $ \Rightarrow \,\,\,\frac{{2R}}{4} + \frac{{{M^2}}}{{12{\rho ^2}{\pi ^2}}}( - 4{R^{ - 5}}) = 0\,\,\,\,\,\,\,\,\,\,\,\,\,$ ($\therefore \,\,M = $ constant) $ \Rightarrow \frac{{2R}}{4} = \frac{{4{M^2}}}{{12{\rho ^2}{\pi ^2}{R^5}}} \Rightarrow {R^6} = \frac{2}{3}\frac{{{M^2}}}{{{\rho ^2}{\pi ^2}}}$ $ \Rightarrow \,\,\,{R^6} = \frac{2}{3}.\frac{{{\rho ^2}{\pi ^2}{R^4}{L^2}}}{{{\rho ^2}{\pi ^2}}}\,\,\,\,\,\,\,\,\,\,\,\,$ [from Eq.(i)] $ \Rightarrow \,\,\,{\left( {\frac{R}{L}} \right)^2} = \frac{2}{3} \Rightarrow \frac{L}{R} = \sqrt {\frac{3}{2}} $ Hence, option (3) is correct.

The correct Option is "$\sqrt {\frac{3}{2}} $"

Consider the following statements. A and B and identify the correct answer given below. I. Body initially at rest is acted upon by a constant force. The rate of change of its kinetic energy varies linearly with time. II. When a body is at rest, it must be in equilibrium.

$KE = \frac{1}{2}m{v^2} = \frac{1}{2}m{\left( {at} \right)^2} = \frac{1}{2}m{a^2}{t^2}$ Rate of change of KE $\frac{{dk}}{{dt}} = \frac{d}{{dt}}\left( {\frac{1}{2}m{a^2}{t^2}} \right) = m{a^2}t,\,\,{ \because }\;\frac{{dk}}{{dt}} \propto t$ So, statement A is correct. When the body is at rest then it may be or may not be in equilibrium, so statement B is wrong.

The correct Option is "A is correct and B is wrong"

A transverse wave is represented by $y = A\,\,\sin \left( {wt - kx} \right)$. For what value of the wavelength is the wave velocity equal to the maximum particle velocity

Wave velocity $ = n\lambda = \omega A \Rightarrow \lambda = \frac{{\omega A}}{{\frac{\omega }{{2\pi }}}} = 2\pi A$

The correct Option is "$2\pi A$"

n drops of each radius r and carrying a charge q are combined to form a bigger drop. The ratio of potentials of bigger to that of smaller is.

For big drop radius $R = {n^{1/3}}r$ For big drop charge $Q = nq$ For big drop capacity ${C^1} = 4\pi { \in _{\rm{o}}}R = 4\pi { \in _{\rm{o}}}{n^{1/3}}r$ ${C^1} = {n^{1/3}}C$ Potential ${V^1} = \frac{Q}{{{C^1}}} = \frac{{nq}}{{{n^{1/3}}C}} = \frac{{{n^{2/3}}q}}{C} = {n^{2/3}}V$ Of big drop $\therefore \frac{{{V^1}}}{V} = \frac{{{n^{2/3}}}}{1}$

The correct Option is "${n^{\frac{2}{3}}}:1$"

A cord is used to lower vertically a block of mass M by a distance d with constant downward acceleration $\frac{g}{4}$. Work done by the cord on the block is

When the block moves vertically downward with acceleration $\frac{g}{4}$ then tension in the cord $T = M\left( {g - \frac{g}{4}} \right) = \frac{3}{4}Mg$ Work done by the cord $\vec F.\vec S = FS\cos \theta \,,\, = Td\cos 180^\circ $ , $ = \left( { - \frac{3}{4}\;Mg} \right) \times d = - 3Mg\frac{d}{4}\;$

The correct Option is "$ - 3\;Mg\frac{d}{4}$"

A bar magnet is held at right angles to a uniform magnetic field. The couple acting on the magnet is to be halved by rotation it from this position. The angle of rotation is

Torque, $\tau = MB\sin {\rm{\theta }}$ Where $\;{\rm{\theta }} = 90^\circ $ $\therefore \;\;\;\;\;\;\tau = MB$ Given, ${\tau _2} = \frac{1}{{2\;}}{\tau _1}$ $\therefore \;\;\;MB\;\sin {\rm{\theta }} = \frac{1}{2}\;MB$ $\therefore \;\;\;\;{\rm{sin\;\theta }} = \frac{1}{2}{\rm{\;}}$ $ \Rightarrow \;\;\;\;{\rm{\theta }} = 30^\circ $ Angle of rotation is =90°-30°=60°

The correct Option is "$60^\circ $"

The resultant of two vectors of magnitudes 2A and ${\sqrt 2 A\;}$ acting at an angle $\theta $ is $\sqrt {10} A$. The correct value of $\theta $ is

$10{A^2} = 4{A^2} + 2{A^2} + 2 \times 2A \times \sqrt 2 A \times {\rm{cos\theta }}$ , or $4{A^2} = 4\sqrt 2 A\cos \theta \,\,or\,{\rm{cos\theta }} = \frac{1}{{\sqrt 2 }} \Rightarrow {\rm{\theta }} = 45^\circ $

The correct Option is "${45^0}$"

The width of a single slit if the first minimum is observed at an angle $2^\circ $ with a light of wavelength $6980\;\mathop {\rm A}\limits^ \circ $

The angular distance $(\theta )$ is given by $\theta = \frac{\lambda }{d}$ $\theta = 2^\circ = \frac{\pi }{{180}} \times 2,\lambda = 6980\mathop {\rm A}\limits^ \circ $ $ = 6980 \times {10^{ - 10}}\;{\rm{m}}$ $ \Rightarrow d = \frac{\lambda }{\theta } = \frac{{6980 \times {{10}^{ - 10}} \times 180}}{{3.14 \times 2}} = 1.89 \times {10^{ - 5}}\;{\rm{mm}}$ $ \Rightarrow d = 2 \times {10^{ - 5}}\;{\rm{mm}}$

The correct Option is "$2 \times {10^{ - 5}}\;{\rm{mm}}$"

The maximum height attained by a projectile when thrown at an angle $\theta $ with the horizontal is found to be half the horizontal range. Then $\theta $ is equal to

${\rm{Maximum\;height}},{\rm{\;}}H = \frac{{{u^2}{\rm{si}}{{\rm{n}}^2}{\rm{\theta }}}}{{2g}}$ , ${\rm{Range}},{\rm{\;R}} = \frac{{{u^2}{\rm{sin}}2{\rm{\theta }}}}{{\rm{g}}}\,,\,{\rm{Given}}\,{\rm{H}} = \frac{R}{2}$ , $\therefore \;\frac{{{u^2}{\rm{si}}{{\rm{n}}^2}{\rm{\theta }}}}{{2g}} = \frac{{{u^2}2{\rm{sin\theta cos\theta }}}}{{2{\rm{g}}}}\,\,{\rm{or\;\;sin\theta }} = 2{\rm{cos\theta }}$ , ${\rm{or\;\;tan\theta }} = 2\,{\rm{or\;\;\theta }} = {\rm{ta}}{{\rm{n}}^{ - 1}}\left( 2 \right)$