The ratio of the energy of an X - ray photon of wavelength 1 Å to that of visible light of wave length 5000 Å is
EX = hc/λX
And EV = hc/ λV
EX/EV = λV/λX = 5000/1
Hence B is correct.
In a transformer, the output current and voltage are respectively 4 A and 20 V. If ratio of no. of turns in primary to secondary is 2:1, what is the input current and voltage?
When a particle of charge Q and mass M moving with a velocity V enters a magnetic field B, the particle is deflected into a circular path of radius
In the photo electric phenomenon, the number of photo electrons emitted is proportional to
A potentiometer consists of a wire of length 4 m and resistance 10 Ω. It is connected to a cell of e.m.f. 2V. The potential difference per unit length of the wire will be
A boy on a cycle pedals around a circle of 20 mts radius at a speed of 20 m/s. The combined mass of the boy and the cycle is 90 kg. The angle that the cycle makes with the vertical so that it may not fall is (g = 9.8 m/sec2)
For balance, so that it may not fall, angle θ made with the vertical
A milliammeter of range 10 mA has a coil of resistance 1 Ω. To use it as voltmeter of range 10 volt, the resistance that must be connected in series with it, will be
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
Minimum kinetic energy is always zero.
Maximum kinetic energy = E−W0 = 6eV−4eV = 2eV
Light of frequency v is incident on a certain photoelectric substance with threshold frequency v₀. The work function for the substance is
In an electron gun, the electrons are accelerated by the potential V. If e is the charge and m is the mass of an electron, then the maximum velocity of these electrons will be
Transformers are used in
The de-Broglie wavelength of a neutron when its kinetic energy is K is λ. What will be its wavelength when its kinetic energy is 4 K ?
Maxwell in his famous equation of electromagnetism introduced the concept of
Heat radiations propagate with the speed of
A straight wire of length l and electric dipole moment p is bent to from a semicircle. The new electric dipole moment would be
Two spherical conductors of radii 4 cm and 5 cm are charged to the same potential. If σ₁ and σ₂ be the respective values of the surface density of charge on both the conductors, then the ratio σ₁/σ₂ is
Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be
If a metallic sphere gets cooled from 62°C to 50°C in 10 minutes and in the next 10 minutes gets cooled to 42°C, then the temperature of the surroundings is
Absolute temperature can be calculated by
Consider two unequal masses m₂ > m₁ connected by a string which passes over a frictionless and massless pulley. The tension T in string is
A current passing through a circular coil of two turns produces a magnetic field B at its centre. The coil is then rewound so as to have four turns and the same current is passed through it. The magnetic field at its centre now is
When 2 A current is passed through the coil of a tangent galvanometer, it gives a deflection of 45°. For 60° deflection, the current must be
Magnetic moment of a magnet is M. Maximum value of torque acting on this magnet when suspended in a uniform magnetic field of intensity B is
The potential energy of a molecule increases when it is brought to the surface from the interior of a liquid because
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
The nucleus finally formed in fusion of protons in proton-proton cycle is
In a Rutherford scattering experiment when a projectile of charge z1 and mass M1 approaches a target nucleus of charge z2 and mass M2, the distance of closest approach is r0. The energy of the projectile is:
In the following reaction, the energy released is
When the bob of a simple pendulum, held in hand is subjected to and fro motion at hill, then the oscillations of the bob will be
When red glass is heated in dark room, it will seem
Continuous emission spectrum is also called
A massless disc of radius r is attached with 5 masses of mass m on its rim. The total moment of inertia of the system is
The linear acceleration of centre of gravity of a ball which rolls down without slipping over an inclined plane with an angle of inclination of 30° will be
The general equation of S.H.M. is
When a P-N junction diode is forward biased then
P-N junction diode works as a insulator, if connected
A 500 watt heating unit is designed to operate from a 115 volt line. If the line voltage dropes to 110 volt, the percentage drop in heat output will be
540 g of ice at 0°C is mixed with 540 g of water at 80°C. The final temp. of the mixture in °C will be
The amount of heat required to melt 540g of ice is given by
= 540 × 80 = 43200 cal
(latent heat of ice = 80 kcal ⁄ g)
Now heat lost by 540 g of water form 80°C to 0°C.
= 540 × 1 × (80° − 0°) = 43200 cal
Therefore, all the ice must be melt and temperature of mixture is zero.
In an experiment, the temperature of a gas in kelvin increases 2 times, when it is suddenly compressed. What is the ratio of initial volume to the final volume of the gas, if the ratio of specific heats is 1.4?
Temperature can be expressed as a derived quantity in terms of any of the following
If an open pipe of length l vibrates in fundamental mode, then pressure variation is maximum at
Tube A has both ends open while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube A and B is
The kinetic energy of a body of mass 2 kg and momentum of 2 Ns is
A metal ball falls from a height of 32 m on a steel plate. If the coefficient of restitution is 0.5, to what height will the ball rise after second bounce
Two masses of 1 kg and 16 kg are moving with equal K.E. The ratio of magnitude of the linear momentum is
Which of the following cannot be made by using Williamson's synthesis?
In which of the following reactions, aldehydes and ketones are distinguished?
Consider the ground state of Cr atom (Z = 24), the number of electrons with the azimuthal quantum numbers l=1 and 2 respectively:
Which of the following is not isoelectronic?
The most reactive nucleophile among the following is
Although due to +I effect of methyl groups, (CH3)2 CHO and (CH3)3 CO are stronger bases but due to steric hindrance both are weaker nucleophiles than CH3O
Further due to resonance, C6H5O
is the weakest nucleophile
CH3O is most reactive (stronger) nucleophile
On heating glucose with Fehling's solution we get a precipitate whose colour is
In the following reaction ,product P is
In a double bond connecting two atoms, there is a sharing of
H₂O is dipolar whereas BeF₂ is not. It is because
The enthalpy of combustion of C(graphite) and C (diamond) are -393.5 and -395.4 KJ mol⁻1 respectively .The enthalpy of conversion of C(graphite) to C (diamond) in KJ mol⁻1 is
Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are -382.64 KJ mol⁻1 and -145.6 KJ⁻1mol⁻1,respectively.The standard Gibb's energy change for the same reaction at 298 K is
Given, ∆H = -382.64 kJ mol-1 and ∆S = -145.6 JK-1mol-1
∆G = ∆H-T∆S
= -382.64 -298(-145.6/1000)
= -339.3 kJ mol-1
In a reversible reaction, the catalyst
A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be k1 and k2 respectively. Then
A particular reaction has a negative value for the free energy change. Then at ordinary temperature
The number of optical isomers of the compound CH₃CHBrCHBrCOOH is
To calculate the amount of work done in Joules during a reversible isothermal expansion of an ideal gas, the volume must be expressed in
The number of isomers exhibited by [Cr(NH₃)₃Cl₃] is
The additive used in composite propellants is
During electrolysis, the species discharged at cathode are
K₄[Fe(CN)₆] is a
The element, which forms oxides in all oxidation states + 1 to + 5, is
Oxidation no. of Os in OsO₄ is
The CO₂ content in the atmospheric air by volume is about
Potassium crystallises in a body centred lattice. Hence, the coordination number of potassium in potassium metal is
In the given reaction, the oxide of sodium is...
4Na + O₂ → 2Na₂O.
Na₂O + H₂O → 2NaOH
The compressibility factor of an ideal gas is
The weight of 11.2 litres of CO₂ at S.T.P. would be
What is the number of free electrons present on each carbon atom in graphite
Which of the following can give iodometric titration?
Which one of the following is acid salt?
Ammonium ion is
Arrange the following halides in the decreasing order of SN1 reactivity.
In Kjeldahl's method, the nitrogen presence is estimated as
Among the bromide I-III given below, the order of their reactivity in the SN1 reaction is:
Orlon is a polymer of
The correct order of increasing basic nature in aqueous solution for the amines listed (I) to (V)
V. (CH3)2 CH — NH — CH (CH3)2
Two elements X(atomic mass = 75) and Y (atomic mass = 16) combine to give a compound having 75.8% X. The formula of the compound is
Oxidation number of iron in potassium ferrocyanide, K₄[Fe(CN)₆] is
An aqueous solution containing 1 g of urea boils at 100.25°C. The aqueous solution containing 3 g of glucose in the same volume will boil at (Molecular weight of urea and glucose are 60 and 180 respectively)
Elevation in boiling point when urea is dissolved in water:
As wt. of water is constant, hence can be neglected.
K b = 100.25 x 60 = 6015
Elevation in boiling point when glucose is dissolved in water:
The vapour pressure at a given temperature of an ideal solution containing 0.2 mol of a non-volatile solute and 0.8 mol of solvent is 60 mm of Hg. The vapour pressure of the pure solvent at the same temperature will be
The concentration units independent of temperature would be
According to the adsorption theory of catalysis, the speed of the reaction increases because
When KI and CuSO₄ solutions are mixed, it gives
Brass is an alloy of
The sexual reproduction is absent in
Nostoc belongs to cyanophyceae. In this entire class sexual reproduction is completely absent. It reproduces by colony formation, hormogonia, akinetes, heterocysts and endospres. However genetic recombination has been observed. It may be probably through transformation or conjugation. The other three algae- Spirogyra, Ulothrix and Volvox belong to chlorophyceae. The members of this class show isogamous, anisogamous and oogamous type of sexual reproduction.
Axolotl is the name given to the larva of:
In a plant organ covered by periderm, the stomata are absent. Gaseous exchange occurs through
In which plant sex organs are embedded in thallus
In Funaria stomata are present on the
In mitosis, the duplication of chromosomes occurs during
Liquid food drinking is
Meiosis II fails after completion of Meiosis I. The phenomenon is
A prokaryotic cell lacks
Hexaploid wheat is
Deficiency of VIII factor leads to
Which are the largest of the white blood cells?
Which factor promotes the appearance of the platelet plug?
Which of the following is not involved in coagulation?
Which of these factors will increase the RBC or RCC?
The present population of the world is estimated to be :
The tests that are used in the diagnosis of AIDS are :
Human population follows :
Where are the lacteals located?
pH of gastric juice is
The gastric juice is highly acidic in nature due to the presence of hydrochloric acid.
An ecosystem has two components such as
Coenzymes FMN and FAD are derived from vitamin
Brain sand is found in
Savannah is found commonly in
Hypophysectomy results in
In competitive inhibition
We are living in
Incomplete dominance produces in F₂ generation
In a cross between pure tall Pea plant with green pods and dwarf Pea plant with yellow pods, how many short plant out of 16 would you expect in F2 generation?
Pollination in Pinus occurs at
The Gymnosperms do not have -
Select the statement which is not correct?
Polygenic character is controlled by multiple genes – True, because many genes control a single character.
Numerous intermediate types are found in between the two extremes in polygenic inheritance – True because many phenotypes are appear between the parental phenotypes.
Height, weight and skin colour are polygenic – True, because many genes control variety of phenotypes in the living organisms.
Polygenic traits is controlled by multiple alleles – False, because many controls the one trait. It is called Polygenic inheritance.
So, the correct option is ‘Polygenic trait is controlled by multiple alleles’.
Membranous labyrinth is concerned with
Which is not an immunological technique?
A compound formed in an organism for inhibiting of another organism is
Snake moulting consists of
Immunity acquired after an infection is
A fixed animal generally possesses
Radial symmetry is seen in sedentary animals where the environment is same along all the radius, consequently, the body is also the same along all the radius. It allows the animal to detect food or danger approaching from any side. Radial symmetry is found in cnidarians, ctenophores and echinoderms.
Bacterial pili are involved in
Lipids are insoluble in water, because lipid molecules are
In photosynthesis, splitting of water moleule and release of oxygen, is called
Which of the following is wrong in relation to photorespiration ?
Sand culture is a component of
In cockroach, the structure which is not associated with mouthparts is
Of the two pairs of wings in cockroach at rest
In Pheretima septa do not occur in
Salivary gland in earthworm is found in
The vascular bundle in a dicot stem is
Phloem serves as a passage for
Phloem provides a passage for the downward movement of food manufactured in the leaves to various parts of the plant.
Identify the plant in which vegetative propagation is possible by using tuber with a node (eye)
A person with a damaged medulla oblongata would have difficulty
In which the following plants vegetative reproduction takes place with the help of bulbils
Benthoic animals live
A number of geographical forms occur in an otherwise freely inbreeding species. The species is
H.G.Khorana was awarded the Nobel prize for
Which of the following is not a fish?
Creosote is used to prevent
What does Bt stand for popular crop of Bt cotton
The most important discovery of the present century is
Insulin is secreted by
Haploid plant cultures are got from
Stele consists of
The application of engineering and technological principles to the life sciences is called
Yogurt is formed by
Bordered pits occur in
The noise created at the launching of space rocket measures around
Minamata disease first occurred in
Biotic succession is caused by
Solenocytes are the main excretory structures in
Seedless fruits can be obtained by the application of
Middle layer of anther wall is formed by secondary outer parietal layer in
The most diverse chemicals are
The sperm penetrates the egg by means of enzymes that are found in the
Vivipary may be described
Xenia indicates the effect of pollen on
Which of the following symptoms might be an indication of kidney failure?