A coil of inductance 40 H is connected in series with a resistance of 8 Ω and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is
In photoelectric phenomenon, the number of photo electrons emitted depends on
Photoelectric current depends on the intensity of incident light, the number of photoelectrons emitted per second is directly proportional to the intensity of incident radiation.
Identify that set in which all the three sustances are good conductors of electricity
An air capacitor of capacity C = 10μ F is connected to a constant voltage battery of 12 volt. Now the space between the plates is filled with a liquid of dielectric constant 5. The charge that flows now from battery to the capacitor is
C = 10 μ F
Charge in capacitor q = CV
= 10 x 12
= 120 μ C
On keeping liquid of dielectric constant5, capacity will becomes of 5 time.
∴ Charge q = 5 x 120
= 600 μ C
Photons of energy 6eV are incident on a metal surface whose work function is 4eV. The minimum kinetic energy of the emitted photoelectrons will be
The stopping potential (V₀)
A shell is fired from a canon with velocity v m/sec at an angle θ with the horizontal direction. At the highest point in its path it explodes into two pieces of equal mass. One of the pieces retraces its path to the cannon and the speed in m/sec of the other piece immediately after the explosion is
Let '2m' be the mass of the cannon which is projected with velocity 'v' at an angle 'θ' with the horizontal direction
The horizontal component of the velocity of the cannon is, vx = v cosθ.
This component remains constant
At the maximum height, the cannon has only this component as the vertical component is momentarily zero
So, momentum before exploding = 2mv cosθ
After exploding one of the masses retraces the path of the cannon backwards
This is possible on if the part has velocity '-v cosθ'
Therefore, momentum after explosion = -mv cosθ + mu
So, by conservation of momentum
2mv cosθ = -mv cosθ + mu
⇒ u = (3v cosθ) m/s
The power factor of a series LCR circuit when at resonance is
Choke coil works on the principle of
What is the de Broglie wavelength of the α-particle accelerated through a potential difference V
A metal plate gets heated, when cathode rays against it, due to
The magnetic flux of 500 micro-webers passing through a 200 turn coil is reversed in 20 x 10-3 seconds. The average e.m.f. induced in the coil in volts is
Induced emf in the coil
= 10 volts
Out of the folowing statement which is NOT true?
In an oscillating LC circuit the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is
A particle of mass m is moving in a horizontal circle of radius r under a centripetal force equal to - K/r2, where K is a constant. The total energy of the particle is
A long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be
The initial temperature of a body is 80ºC. If its temperature falls to 64ºC in 5 minutes and in 10 minutes to 52ºC then the temperature of surrounding will be
An electric lamp is marked 60 W, 220 V. The cost of kilo watt hour of electricity is Rs 1.25. The cost of using this lamp on 220 V for 8 hours is
An infinite long plate has surface charge density σ . As shown in the figure a point charge q is moved from A to B. Net work done by electric field is:
An electric dipole has the magnitude of its charge as q, and its dipole moment is p. It is placed in a uniform electric field E. If its dipole moment is along the direction of the field, then force acting on it and its potential energy are respectively
The situation is shown in adjacent figure is parallel to
∴ U = - pE cos 0 = - pE = Minimum
and the net force on the dipole is zero
For protecting sensitive equipment from external magnetic field, it should be
A bar magnet of pole strength 20 A-m is divided into 4 equal parts by slicing it along lines parallel to its length and breadth, passing through centre. The pole strength of each piece is
Two wires of the same material and length, but diameters in the ratio 1 : 2 are stretched by the same force. The elastic potential energy stored per unit volume for the two wires when stretched, will be in the ratio of
When a train stops suddenly, passengers in the running train feel an instant jerk in the forward direction because
To impart high energy to sub atomic particles, the particle accelerator used is
A body of mass 2 kg is made to oscillate with an angular frequency 4 rad-s⁻1 on a spring. The force constant of the spring is
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Air quickly leaking out of a balloon becomes cooler.
Reason(R): The leaking air undergoes adiabatic expansion. Reason(R): The leaking air undergoes adiabatic expansion.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Coulomb's law gives the electric field due to a distribution of charges , while Biot-Savarts law gives the magnetic field due to a current element .
Reason(R): A stationary charge generates an electric field while a current generates a magnetid field in the surrounding space.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A particle of mass m collides with another stationary particle of mass M. If the particle m stops just after the collision, the coefficient of restitution of collisions is equal to 1.
Reason(R): Momentum of system just before and after the collision remains constant.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A lens of water formed by very thin convex glass layer has lesser focal length than a double convex lens of glass.
Reason(R): Refractive index of glass is more than that of water.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The brightness of a light bulb in a room decreases when a heavy current appliance is switched on.
Reason(R): There will be no change in the brightness of bulb if the source is ideal.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When a body is projected with velocity v = v0 (where v0 is orbital velocity) then path of the projectile is circular.
Reason(R): Gravitational force between body and the earth provides the centripetal force.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The resistivity of a semiconductor increases with temperature.
Reason(R): The atoms of semiconductor vibrate at larger amplitude at higher temperature, thereby increasing resistivity.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Radio waves can be polarized.
Reason (R): Sound waves in air are longitudinal in nature.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A capacitor and a resistor are connected in series with an a.c. circuit. In this circuit current and potential difference across the resistance leads potential difference across the capacitor by and angle π/2.
Reason(R): In C-R circuit voltage lags behind the current by phase angle which depends on the value of C and R.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Any internal forces in the system are included while considering force for Newton's second law of motion.
Reason(R): The force in the law stands for the net force on the system.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): In a system with damping effect, 100% of the total energy can be the maximum potential energy.
Reason(R): Minimum potential energy will be treated as zero point energy and will also be non-zero.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Air close to the equator of our earth has an eastward speed.
Reason(R): Rotation of the earth modifies the path of the air molecules.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The maximum frequency of the photon produced by the union of a positron and an electron is 1.2x1020Hertz.
Reason(R): In electron-positron collision, both are annihilated and the total mass is converted into γ-photon(energy).
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A closed pipe produces only old harmonics, while an open pipe produces only even harmonics.
Reason(R): Closed end of the pipe reflects the longitudinal wave like a rigid boundary while the open end reflects the longitudinal wave like a free boundary .
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Time period of a hollow ball will be more than that of a solid ball of same radius.
Reason(R): Time period is independent of mass or distribution but on l , where l is the distance between the point of suspension and the centre of the bob.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Costly wrist watches and other instruments are enclosed in a soft-iron case to protect it from external field.
Reason(R): Iron-case is used as magnetic screening or shielding.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): There is no charge in the energy of a charged particle moving in a magnetic field although a magnetic force is acting on it.
Reason(R): The force on a moving charge acts parallel to its direction of motion.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): An astronaut accidentally gets separated out of his small spaceship accelerating in intersteller space at a constant rate of 90ms⁻2. The acceleration of the astronaut at the instant he is outside the spaceship is more than 90ms⁻2.
Reason(R): More forces act on the astronaut the moment he is out of spaceship.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When a light wheel of mica is placed in the path of cathode rays, it starts rotating.
Reason(R): Cathode rays produce heat when they strike a material surface.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When a beetle moves along the sand within a few centimetres of scorpion, the scorpion immediately turns and dashes towards it.
Reason(R): When a beetle disturbs the sand, it send pulses along the sand's surface through which scorpion detects the beetle.
An electric motor exerts a force of 40 N on a cable and pulls it by a distance of 30 m in one minute. The power supplied by the motor is
A stone thrown at an angle θ to the horizontal reaches a maximum height h. The time of flight of the stone is
A double convex lens of glass μ = 1.5 is immersed in water μ = 4/3 . If the focal length of the lens in air is ′ f ′ . Focal length in water is
In a spectrometer experiment three prisms A, B, C with same angle of prism but of different materials of refractive indices μA = 1.33 , μB = 1.55 and μC = 1.44 are used. The corresponding angles of minimum deviation DA , DB , DC measured will be such that
The dark lines in the solar spectrum are due to
Consider the two following statements A and B and identify the correct choice even in the answers (A) Duddells thermo-galvanometer is suitable to measure direct current only (B) Thermopile can measure temperature differences of the order of 10⁻3ºC
Electrical conductivity of a semiconductor
The transistors provide good power ampli-fication when they are used in
If the acceleration due to gravity is 10ms⁻2 and the units of length and time are changed in kilometer and hour respectively, the numerical value of the acceleration is
Dimensional formula for torque is
A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is
Inverse square law of intensity (illuminance) is valid for
Soap bubble looks coloured due to
Under the action of a force, a 2 kg body moves such that its position x as a function of time is given by x = t2/3, where x is in meters and t is in sec. The work done by the force in the first two seconds is
The number of atoms contained in 11.2 L of SO₂ at S.T.P. are
Methanol is manufactured by
2 g of oxygen contains number of atoms equal to that in
The most reactive compound for electrophilic nitration is
Toluene on oxidation with chromyl chloride produces
A group which deactivates the benzene ring towards electrophilic substitution but which directs the incoming group towards o- and p-positions is
In graphite, the electrons are
Freon is used as a
Which of the following is soluble in water?
The rate of a first order reaction is 1.5 X 10⁻2 mol-L⁻1-min⁻1 at 0.5M concentration of the reactant. The half -life of the reaction is
The units for the rate constant of first order reaction is
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): [Cr(NH3)6]3+ is paramagnetic
Reason(R): [Cr(NH3)6]3- shows d2sp3 hybridi-sation, with three unpaired electrons.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The presence of Ag⁺ enhances the solubility of alkenes in water.
Reason(R): Alkenes are weakly polar in nature.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Ionisation energy of F is numerically same to that of its electron affinity but with different sign .
Reason(R): Ionisation energy and electron affinity both depend upon size and effective nuclear charge.
Calculate Δ H in KJ for the following reaction C(s) + O2g → CO2g Given that
H2O (g) + C (g) → CO (g) + H2 (g), ΔH = +131kJ
CO (g) + → CO2 (g), ΔH = -282kJ
H2 (g) + → H2O (g), ΔH = -242kJ
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The number of electrons present in 3f sub-shell is 14.
Reason(R): f sub-shell can accomodate 2 x 7 electrons.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Beryllium halides dissolve in organic solvents.
Reason(R): Beryllium halides are ionic in character.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Hard water does not form lather with soap.
Reason(R): In hard water, the sodium stearate of soap changes to the corresponding calcium magnesium salt which precipitates out.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): For the process to be spontaneous ∆G as well as ∆S has to be less than zero.
Reason(R): For spontaneous change, ∆STotal > 0.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): In aluminothermy Cr₂O₃ is reduced with Al.
Reason(R): Aluminium is more electro-positive than chromium.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Phosphorus is one of the least electronegative of non-metals.
Reason(R): It reacts with non-active metals to form p3- ion.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Hydrogen has only one elctron in its orbit but it produces several spectral lines.
Reason(R): There are many excited energy levels available.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Benzene reacts with CH3COCl to form chlorobenzene in presence of AlCL3.
Reason(R): Chlorination is an electrophilic substitution reaction.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): One can safely use phenolphthalein as indicator between the titration of weak acid and strong base.
Reason(R): Phenolphthalein indicator, pH range is 4.2-6.0.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): NO3- is planar while NH3 is pyramidal.
Reason(R): N in NO3- is sp2 hybridised but in NH3 it is sp3 hybridised.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): According to the principle of common ion effect , the solubility of HgI2 is expected to be less in an aqueous solution of KI than in water. but HgI2 dissolves in an aqueous solution of KI to form a clear solution.
Reason(R): Iodine ion, I-, is highly polarisable.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): NaCl + AgNO3 → AgCl + NaNO3 is an ionic reaction .
Reason(R): For an ionic reaction , the sum of total ion charges on each side, as well as the number of each kind of atom on each side, must balance.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Al(OH)3 is amphoteric in nature.
Reason(R): Al-O and O-H bonds can be broken with equal ease in Al(OH)3.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): No heat engine has efficiency of 100%.
Reason(R): It is not possible to convert all the heat into work.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): La(OH)2 is more basic than La(OH)3.
Reason(R): The basic character of oxides and hydroxides decreases from La(OH)3 to Lu(OH)3.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): The hydrogens of the CH2- group of 1,3-cyclopentadiene are acidic and this hydrocarbon is nearly 1030 times more acidic than ordinary alkanes.
Reason(R): In cyclopentadienyl anion, all five cabons are equivalent as demonstrated by labelling experiments.
The oxidation no. of nitrogen in NaNO₂ is
The formal oxidation state of the nitrogen atom in a nitrite is +3. This means that it is can be either oxidised to oxidation states +4 and +5 or reduced to oxidation states as low as -3.
An electrolytic cell contains a solution of Ag2SO4 and have platinum electrodes. A current is passed until 1.6 gm of O2 has been liberated at anode. The amount of silver deposited at cathode would be
Wt. of O2 = 1.6 g; Wt. of Ag deposited = ? ;
Eq. Wt. of oxygen = 8, Eq. Wt. of Ag = 108
We know :
Real gases deviate from ideal behaviour because ,the molecules
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): It is difficult to cook food on hills.
Reason(R): The boiling point of water increases at increase in attitude.
Which of the following metal can be easily cut with a knife?
Which one of following properties of alkali metals increases in magnitude as the atomic number rises?
Microcosmic salt is
On boiling an aqueous solution of KClO₃ with I₂ the prodcuts obtained are
One mol of magnesium nitride on reaction with an excess of water gives
Which of the following is formed when magnesium reacts with nitrogen?
Precipitation takes place when the ionic product
Which of the following is a strong electrolyte?
Which of the following is a method of converting a ketone to hydrocarbon with same number of carbon atoms?
Which of the following reactant in the presence of AlCl₃ gives acetophenone?
The dissociation constant is highest for
Following stepis:
Why only As⁺3 gets precipitated as As₂S₃ and not Zn⁺2 as ZnS when H₂S is passed through an acidic solution containing As⁺3 and Zn⁺2?
The addition of HBr to alkenes in the presence of peroxides is called :
Conc.HNO3 forms in presence of:
p-type silicon is formed by adding a minute amount of an element with
Which does not contain conjugate system?
In dienes, when the double bonds connected to each other by a single bond, this arrangement is known as conjugated.
Quartz is a crystalline variety of
When molten Zn is cooled to solid, it assumes HCP structure. Then the number of nearest neighbours of Zn atoms will be
If 480 ml of 1.5 M solution and 520 mL of 1.2 M solution is mixed, then molarity of the final solution is
Liquid benzene burns in oxygen according to following equation.
2 C₆H₆(l) + 15 O₂(g) → 12 CO₂(g) + 6H₂O(g)
How many litres of oxygen are required for complete combustion of 39 gram of liquid benzene ?
Which of the following is not a colligative property?
Which of the following properties are not correct for enantiomers?
Who was awarded Nobel Prize in chemistry for discovering laws of osmotic pressure for solution?
Copper is extracted from copper pyrites ore by heating in a blast furnace. The method is based on the principle that
Kupffer cells are involved in
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): The honey bee queen copulates only once in her life time.
Reason(R): The honey bee queen can lay fertilized as well as unfertilized eggs.
Queen is the only fertile female in beehive, having immensely developed ovaries. She lives for several successive years laying about 2000 or more eggs a day and upto 1,500000 eggs during her life time. The queen has a remarkable capacity of controlling the fertilization of its eggs. A fertilized egg is laid in a worker or queen cell or honey comb, while an unfertilized egg in a drone cell, the later developes parthenogenetically. The queen mates only once in lifetime. The sperms stored in her spermatheca fertilize her eggs as long as she lives.
Flightless bird cassoway is native of
Which of these feeds upon dead organic matter with its maxillae picking up the food particles and bringing these to mandibles for mastication ?
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Dormancy is required for good survival of seeds.
Reason (R): Dormant seeds serve the major part of our food.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): The seeds have two separable seed coats, testa and tegmen.
Reason (R): Inner to testa is present in the embryo.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Leaves are present in different planes of branch.
Reason (R): A branch possesses leaf at terminal position.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Flowering in plants occurs only when the length of dark period is suitable.
Reason (R): The flowers are the receptors of the photoperiodic stimulus.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Aldosterone is a steroid hormone and is important in the control of sodium and potassium ion concentration in mammals.
Reason(R): It upgrades sodium ion concentration in the ECF by promoting reabsorption of sodium ions from renal tubules and excretion of postassium ions in urine.
Aldosterone is a hormone that increases the reabsorption of sodium ions and water and the release (secretion) of potassium ions in the distal convoluted tubules of the kidneys. This increases blood volume and, therefore, increases blood pressure.
Acting on the nuclear mineralocorticoid receptors (MR) within the principal cells of the distal tubule and the collecting duct of the kidney nephron, it upregulates and activates the basolateral Na+ or K+ pumps, stimulating ATP hydrolysis leading to phosphorylation of the pump and a conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, hence reabsorbing sodium (Na+) ions and water into the blood, and secreting potassium (K+) ions into the urine. Aldosterone stimulates uptake of K+ into cells.Aldosterone stimulates Na+ and water reabsorption from the gut salivary and sweat glands in exchange for K+. Aldosterone stimulates H+ secretion by intercalated cells in the collecting duct, regulating plasma bicarbonate (HCO3-) levels and its acid/base balance.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Rhoeo leaves contain anthocyanin pigments in epidermal cells.
Reason(R): Anthocyanins are accessory photosynthetic pigments.
Anthocyanin is a colouring pigment of certain higher plants that imparts a bluish or reddish colour.
Rhoeo leaves contain anthocyanin pigments in epidermal cells.
In the following questions, a statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the statements carefully and mark the answer-
Assertion (A): Totipotency can be easily demonstrated in plant cells.
Resaon (R): In higher animals it has not yet been experimentally proved.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Water absorption is reduced by lowering O2 tension.
Reason (R): The accumulation of CO2 reduces water absorption.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Auxins are found in the growing tips of the plant.
Reason (R): The concentration of auxins is highest at the tip of the root.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Ionizing radiations are harmful for the living organism.
Reason(R): They form toxic photoproducts in the cells.
The ionizing radiations can have direct effect on chromosomes. They may directly break chromosomes or alter one of the DNA bases or indirectly may initiate a chain of chemical reactions. The biological effect also depends on the kind of cell and stage of nuclear cycle.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it.Read the Statement carefully and mark the correct answer-
Assertion(A): Unisexual flowers have separate male and female flowers.
Reason (R): Both monoecious or dioecious plants have unisexual flowers.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Old age is not an illness. It is a continuation of life with decreasing capacity for adaptation.
Reason(R): Cessation of mitosis is a normal genetically programmed event.
Old age is the result of ageing or senescence which may be defined as the progressive deterioration in structure and function of the body cells, tissues, organs and organ systems of the organism with their advancing age.In old age the body's immune system loses its ability to effectively deal with the antigens. This reduces the resistance as well as adaptation of the body.
Cessation of mitosis is not as such a genetically programmed event. During ageing, there is a decrease in multiplication of cells though it differs in various tissues.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Organ transplantation patients are given immunosuppressive drugs.
Reason(R): Transplanted tissue has antigens which stimulate the specific immune response of the recipient.
When an organ, such as a liver, heart or kidney, is transplanted from one person into another , the immune system of the recipient triggers the same response against the new organ that it would have against any foreign material, setting off a chain of events that can damage the transplanted organ. This process is called rejection. Acute rejection can occur rapidly , or chronic rejection over a long period of time . Rejection can occur despite close matching of the donated organ and the transplant patient. Immunosuppressant drugs greatly decrease the risks of rejection, protecting the new organ and preserving its function. These drugs act by blocking the recipient's immune system so that it is less likely to react against the transplanted organ. A wide variety of drugs are available to achieve this aim but work in different ways to reduce the risk of rejection.
Tissues that are antigenitically similar are said to be histocompatible such tissues do not induce an immunologic response that leads to graft rejection. Tissues displaying significant antigenic differences are histoincompatible; such tissues induce immune response leading to tissue rejection. Antigens that participate in graft rejection are called as transplantation or histocompatibility antigens. The blood group antigens are important in transplantation. The term major histocompatibility system is applied to a system of cell antigens that exert a decisive influence on the fate of allografts. The major antigen system in human beings is the human leucocytes antigen (HLA) system.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Cyclic pathway of photosynthesis first appeared in some eubacterial species.
Reason(R): Oxygen started accumulating in the atmosphere after the non-cyclic pathway of photosynthesis evolved.
Cyclic pathway of photosynthesis appeared for the first time in some Eubacterial species. It is supposed to be the first evidence of production of ATP in the presence of light.
During non-cyclic photophosphorylation photolysis of water takes place. Under the influence of light energy and the catalytic action of chlorophyll, water, a substance of low energy value, is split into oxygen and hydrogen. Oxygen is used in the chloroplast. Non-cyclic photophosphorylation is the only natural process which adds molecular oxygen to the atmosphere.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion (A): The impbalance in concentration of Na+ , K+ and proteins generates resting potential.
Reason (R): To maintain the unequal distribution of Na+ and K+ ,the neurons use electrical energy.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Phloem translocates mostly carbohydrates.
Reason (R): Glucose is the most translocated carbohydrates.
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Generally, a woman does not conceive during the lactation period.
Reason(R): The hormone 'prolactin' initiates and maintains lactation in a postpartum woman.
Generally a woman does not conceive during the lactation period. LActation stimulates prolactin secretion and there is evidence that prolactin inhibits GnRH secretion and antagonizes the action of gonadotropins on the ovaries. Ovulation is inhibited and the ovaries are inactive so estrogen and progestrone output falls to low levels.Only 5 to 10 % chances of getting pregnant are there during lactation period.
Prolactin is a protein hormone of the adenohypophysis of the pituitary gland that induces and maintains lactation in the postpartum mammalian female .
In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Replication and transcription occur in the nucleus but translation occurs in the cytoplasm.
Reason(R): mRNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acid are available for protein synthesis.
DNA replication is the process of forming carbon copy of DNA whereas transcription is the formation of RNA over DNA template.DNA replication and transcription takes place in nucleus as the required material DNA and RNA are present in the nucleus.
During transcription mRNA take the coded information from DNA to the cytoplasm where translation takes place. Translation is the process of protein synthesis. It is separated from transcription in both space and time. It prevents the intermixing of raw materials, protect DNA from respiratory enzymes and ribosomal machinery from nuclease.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Growth rings are also called as annual rings.
Reason (R): Generally growth ring is formed in each year.
Why carbohydrates are more effiecient in providing energy than fats and proteins?
In ABO system of blood grouping, transfusion is not possible from
The major link in transfer of chemical energy is ATP-ADP system was first described by Lipman in-
Which of the following is true of the small intestine?
Hydrogen bonds between cytosine and guanine are :
Which of the following can fix atmospheric nitrogen?
Which of the following pair is incorrect?
Cardamoms are ripe dried fruits of
Who is considered as ancestor of modern apes?
In repressible or negative operon
Wobble hypothesis was proposed by
Which of the following traits of garden pea studied by Mendel was a recessive feature ?
A late acting dominant disorder is
Universal blood donor group is
Basis of vaccination was discovered by
Interferon suppresses the pathogenicity of
Rejection of transplanted organ is due to
Cauliflory is
The hereditary material present in the bacterium E. coli is
Depolarization of a nerve cell is caused by
Mineral present in cytochrome is
Sex factor of bacteria is
The law of limiting factors for photosynthesis was enunciated by
Which is not required for synthesis of carbohydrates
If by radiation all nitrogenase enzymes are inactivated, then there will be no
A living mechanical tissue having cellulosic wall thickening is
Angular collenchyma occurs in
Occurrence of water blooms in a lake indicates