An electric motor operates at 20 r.p.s. What will be the approximate power delivered by the motor, if it supplies a torque of 75 N-m?
Light of wave length λ and photon energy 2eV falling on a metal surface produces photoelectrons of maximum velocity V. If the λ is decreased by 25% and the maximum velocity of electron is doubled, the work function of the metal is (in eV)
In an ideal parallel LC circuit, the capacitor is charged by connecting it to a.c.d. source, which is then disconnected. The current in the circuit
When a resistance of 2 Ω is connected across the terminals of a cell, the current is 0.5 amperes. When the resistance is increased to 5 ohm, the current is 0.25 amperes. The internal resistance of the cell is
A particle is moving on a circular path with constant speed, then its acceleration will be
If the current is halved in a coil, then the energy stored is how much times the previous value
A capacitor is having a capacity of 2 pF. Electric field across the capacitor is changing with a value of 1012 V/s. The displacement current is
A 10 m long wire of 20Ω resistance is connected in series with a battery of 3 volt e.m.f. (negligible internal resistance) and a 10Ω resistance. The Potential gradient of wire in volt per meter is
Net resistance in series R = 20 + 10 = 30Ω
Current in the circuit i = V/R
= 3/30 = 0.1 A
Fall in potential of a wire
V' = 0.1 x 20 = 2 volt
Hence, potential gradient K = V' /l
= 2/10 = 0.2 V/m
Three capacitors each of capacitance C and of breakdown voltage V are joined in series. The capacitance and breakdown voltage of the combination will be:
The capacitance of an isolated spherical conductor of radius 15 cm is
If 1000 droplets each of charge q and radius r are mixed to form a big drop, then the potential of big drop, as compared to small droplet will be
If the value of potential on each small drop be V and potential on each small drop be V '
V ' = n 2/3 V
⇒ V ' = 1000 2/3 V
⇒ V ' = 10 3 2 3 V = 10 2 V = 100 V
A block of weight 200N is pulled along a rough inclined plane of inclination 45o with the horizontal. If the coefficient of friction is 0.5, the retardation is
A man inside an artificial satellite feels weightlessness because the force of attraction due to earth is
Relation between the colour and the temperature of a star is given by
If the radius of earth's orbit is made 1/4, the duration of an year will become
Mean kinetic energy per degree of freedom of gas molecules is
In the Young's double slit experiment, the central bright fringe can be identified
With white light, the central fninge is white so it can be easily identified
A wire is wound in the form of a solenoid of length and diameter d. When a strong current is passed through the solenoid there is tendency to
Two concentric circular coils of ten turns each are situated in the same plane. Their radii are 20 cm and 40 cm and they carry respectively 0.2 A and 0.3 A currents in opposite direction. The magnetic field in tesla at the centre is
The magnetic field at the centre of current I carrying loop of radius r, is
To shield an instrument from external magnetic field, it is placed inside a cabin made of
The field of a short bar magnet at a distance of 1 m on its axial line is 1 oersted. At a distance of 2 m on the same line, the intensity in oersted will be
Bernoulli's theorem is based on the law of conservation of
A magnet of magnetic moment M is cut into two equal parts. The two parts are placed perpendicular to each other so that their north poles touch each other. The resultant magnetic moment is
Magnetic moment of each part = m/2
Resultant magnetic moment of perpendicular magnets =
The excess pressure inside one soap bubble is three times that of a second bubble. The ratio of the volumes of the first bubble to that of second bubble is
A metallic wire is suspended by attaching some weight to it. If α is the longitudinal strain and Y is Young's modulus, then the ratio between elastic potential energy and the energy density is equal to
The moment of inertia of a meter scale of mass 0.6 kg about an axis perpendicular to the scale and located at the 20 cm position on the scale in kg m2 is (Breadth of the scale is negligible)
A force of 100 dynes acts on mass of 5 gm for 10 sec. The velocity produced is
A body falling for seconds covers a distance S equal to that covered in next second. Taking g=10m/s2,S=
Number of neutrons in C12 and C14 are
Out of the following which has no charge?
An astronomical telescope of ten-fold magnification has a length of 44 cm. The focal length of the objective is
Find the kinetic energy of the photoelectrons emitted when light of wavelength 4000 Å is incident on a metal of work function 2 eV (find approximately)
If a body is released into a tunned dug along the diameter of the earth of radius R₀, it executes the S.H.M. with time period:
Relation between the stopping potential V₀ of a metal and the maximum velocity ν of the photoelectrons is
Two bullets are fired simultaneously, horizontally and with different speeds from the same place. Which bullet will hit the ground first?
Critical angle for light going from medium (i) to (ii) is θ. The speed of light in medium (i) is ν. Then speed in medium (ii) is
The astronomical telescope consists of objective and eye-piece. The focal length of the objective is
A convex lens of focal length 0.5 m and concave lens of focal length 1 m are combined .The power of resulting lens will be
A man with defective eyes cannot see distinctly objects at distances more than 60 cm from his eyes. The power of the lens to be used will be
The moment of inertia of a straight thin rod of mass M and length l about an axis perpendicular to its length and passing through its one end, is
The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is
A body of mass 1kg is executing simple harmonic motion. Its displacement 'y' cm at 't' seconds is given by y = 6 sin (100 t + π ∕ 4) . It maximum kinetic energy is
If the drift velocity and mobility of electrons in a semiconductor are represented by ν and μ respectively and the applied electric field is E, then μ is given by
P-N junction is said to be forward biased, when
The equation of a progressive wave is y = 0.5 sin 2 π [ t/0.004 − x/50 ] where y and x are in cm. The phase difference between two points separated by a distance of 5 cm at any instant is
Two resistance thermometers are made, one of the platinum wire and the other of germanium wire. The resistance of both the thermometers are equal at room temperature. The two resistance wires are connected to a battery. Now the two resistance wires are heated to 100oC. The potential drop in the two resistance is measured. Which of the following statement is correct
With rise in temp, the resistance of platinum wire increases but of germanium wire decreases.
Since the current is same in the wires, when connected in series, therefore heat produced ∝ R
The pressure of air in a soap bubble of 0.7 cm diameter is 8 mm of water above the pressure outside. The surface tension of the soap solution is
If two bulbs of wattage 25 and 30, each rated at 220 volts, are connected in series with a 440 volt supply, which bulb will fuse
Safe current through 25 W bulb
Safe current through 30W blub
This is greater than the safe current for 25W bulb, so it will fuse
If a wire of resistance 20Ω is covered with ice and a voltage of 210 V is applied across the wire, then the rate of melting of ice is
The mass of oxygen gas occupying a volume of 11.2 litres at a temperature 27oC and a pressure of 760 nm of mercury in kilograms is (Molecular weight of oxygen =32)
Which of the following p-V diagrams best represents an isothermal process ?
In a reversible isochoric change
The physical quantities not having same dimensions are
S.I. unit of luminous intensity is
If wavelength of a photon is 6000 Å, then energy of this photon will be
The wave theory of light was given by
The speed of transverse vibrations in a stretched string is 700 cm/s. If the string is 2 m long, the frequency with which it resonates in fundamental mode is
A wave is reflected from a rigid support. The change in phase on reflection will be
A rod elongates by l when a body of mass M is suspended from it. The work done is
Which of the following compounds does not form an ozonide?
In its reaction with silver nitrate acetylene shows
An alkyl chloride produces a single alkene on reaction with sodium ethoxide and ethanol. The alkene further undergoes hydrogenation to yeild 2-methylbutane. Identify the alkyl chloride from amongest the following :
Brown ring test is used to detect
The homologue of ethyne is
C2H2 is Ethyne (homologue of alkyne)
C3H4 is propyne (homologue of alkyne)
C3H8 → propane (homologue of alkane)
C2H6 → Ethane (homologue of alkane)
The electrons present in K-shell of the atom will differ in
Which of the following ions has the maximum magnetic moment?
If principal quantum no. of atom is 3, then its azimuthal quantum number is
The alkyl halide is converted into ethyl alcohol by
The shape of H₃O⁺ ion is
The bond order of a molecule is given by
The values of Kp1 and Kp2 for the reactions
are in the ratio of 9:1. If degree of dissociation of X and A be equal, then total pressure at equilibrium (1) and (2) are in the ratio:
For a reaction to occur spontaneously,
Which statement is wrong among the following?
In an endothermic reaction, the value of ∆H is
The heat of formation of CO(g) and CO2(g) are Δ H = − 110 and Δ H = − 393 KJ-mol-1 respectively. What is the heat of reaction ( Δ H ) (in KJ-mol-1) for the following reaction CO g + 1/2 O2 g → CO2 g
Medicine which is an antibiotic is
Which of the following will be have a meso isomer also ?
Which of the following has highest first ionization potential?
Nitrogen has highest first ionization potential. This is because N contains exactly half-filled p-orbitals which is extra stable. hence its first ionisation potential is high.
Some salts although containing two different metallic elements give test for only one of them in solution. Such salts are
The e.m.f. of a galvanic cell with electrode potentials of Al equal to -1.66 V and that of Mg equal to - 0.54 V is
E.M.F. can be positive only if oxidation takes place at Mg-electrode. But here the reduction reaction takes place.
All the following substances react with water. The pair that yields the same gaseous product is
A container contains 1 mole of a gas at 1 atm pressure and 27oC, and its volume is 24.6 ltres. If pressure is 10 atm and temperature 327oC, then new volume is approximately
Which of the following mixture of gases does not obey Dalton's law of partial pressure ?
What are the products formed when Li₂CO₃ undergoes decomposition?
Cl2O7 is an anhydride of
Freon-12 is used as a
What is the hybridisation state of the central atom in the conjugate base of NH₄⁺ ion ?
AlCl₃ exist as dimer because
Which among CH₄, SiH₄, GeH₄ and SnH₄ is most volatile?
Which of the following reaction involves oxidation and reduction?
One which is not dissolved by dilute hydrochloric acid is
The concept that acid is proton donor and base is proton acceptor was given by
Highest pH (14) is shown by
To a solution containing equimolar mixture of sodium acetate and acetic acid, some more amount of sodium acetate solution is added. The pH of mixture solution
Action of water or dilute mineral acids on metals can give
Among the following the strongest acid is
Which of the following will show geometrical isomerism?
Which of the following are the end products of uranium and actinium series?
Which of the following compounds is used as a refrigerant?
An organic compound 'X' on treatment with acidified K₂Cr₂O₇ gives a compound 'Y' which reacts with I₂ and sodium carbonate to form Triodomethane. The compound 'X' is
A magnet will cause the greatest deflection of
Acrolein is prepared from
Wacker's method involves the conversion of alkene using PdCl₂ into corresponding
The addition of HBr to alkenes in the presence of peroxides is called :
The reaction of O₂ with sodium phenoxide at 400 K results in
The formula dichlorobis (urea) copper (II) is
Conc. HNO3 forms NO2+ in presence of :
Nylon thread are made of
In Kjeldahl's method ,nitrogen present is estimated as
The solid NaCl is a bad conductor of electricity since
When KMnO₄ acts as an oxidising agent and ultimately forms MnO₄2- , MnO₂, Mn₂O₃ and Mn+2, then the number of electrons transferred in each case is
In which of the following compounds transition metal is in zero oxidation state?
Benzoic acid undergoes dimerisation in benzene solution. The Vant's Hoff factor 'i' is related to the degree of dissociation 'α' of the acid as
Of the following compounds, which will have zero dipole moment?
The normality of a 2.3 M sulphuric acid solution is
If a beam of light is passed through a true solution, then it
Study the following table
Which two compounds have least weight of oxygen (molecular weight compounds are given in brackets)
%O = wt of organic compound/gram molecular wt of compound x 100
Bell metal is an alloy of
The equivalent weight of KMnO₄ (formula weight = M) when it is used as an oxidant in neutral medium is
Natural parthenogenesis is found in
The opening of the upper chamber of the heart into the lower chamber is known as
Number of chromosome groups at equatorial plate of metaphase I of a plant body having 2n = 50 chromosomes shall be
The stem cells that give rise to all red blood cells, white blood cells, and platelets are known as:
Penetrants or stenoteles are the nematocysts of Hydra, of these
Which type of condition is directly related to bone marrow suppression?
E. coli are beneficial to humans because they
When salivary amylase enters the stomach, it becomes
Mahgany wood is obtained from the plants of family
Coir is the commercial product of coconut's
Which of the following wood is used in making cricket bats?
Cinchona is obtained from
Bordeaux mixture is a fungicide, which consists of
Cast nets are used to catch
Hypophysis is the alternate name of
A treeless biome is
The pyramid of number in grassland ecosystem, is
The major forest type found in India is
Implantation of fertilised egg or young embryo occurs under the influence of
The amino acid substituted in sickle-cell anaemia is :
Two individuals with similar external appearance but different genetic make up have the similar
DNA replication occurs
It is matter of common observation that monocots and dicots have one and two cotyledons respectively but in gymnosperms the number of cotyledons are -
Mendel's work was got republished in 'Flora' by
According to recent studies, the most thickly populated country in the world is
A common characteristic of all vertebrates is
Sedatives and tranquillisers are also called
Between the osseous and membranous labyrinths is present a fluid called
Deficiency of vatimn A in the body results in insufficent rhodopsin in the rods which leads to
Lymph formed in your right hand will eventually drain into the:
The red pulp of the spleen functions to _____.
Which one of the following animals belongs to class Scaphorpoda?
The example of Marsupialia is:
Which of the following is an example of biotic resource of energy?
Minerals absorbed by roots move to the leaf through
Presence of organic substances in the phloem can be demonstrated by means of
Aristotle classified the animals into which of the following groups ?
Chemosynthesis and photosynthesis are similar in being
Indian Telegraph Plant is
Parthenocarpy can be achieved by
Nitrogen fixation occurs in
In which one of the following pathogens do the cells of promycelium after the germination of teleutospore produce infection hyphae instead of basidiospores?
The recent increase in food production is due to
Which of the following is not used for the disinfection of drinking water?
The two great industrial tragedies namely, MIC and chernobyl, respectively occured where and when?
A sponge can be distinguished by the presence of
Vascular tissue is derived from
Number of nuclei participating in double fertilization is
When funiculum, embryo sac, chalaza and micropole lie in one straight line and ovule is called
Eye of Potato is
Ethanol is formed from acetaldehyde by an enzyme called
Alveoli would not be characterised as
Which of the following is caused by the contraction of the diaphragm?
Following are assertion and reason. What is correct combination. Assertion. periplanata americana is nocturnal, omnivorous, household pest. Reason. It is because it acts as scanvenger
Hearts of Pheretima are situated in the segments
Most of the blood glucose entering the nephron returns to the plasma by the process of
Blood entering the kidney is filtered by the
Stomata of CAM plants