The alternating voltage induced in the secondary coil of a transformer is mainly due to
A varying magnetic field produces an emf which is the underlying principle of transformers.
Photons of energy 1eV and 2.5 eV successively illuminate a metal whose work function is 0.5 eV. The ratio of the maximum speeds of the electrons emitted will be
What is the de Broglie wavelength (in Å) of the alpha- particle accelerated through a potential difference V ?
A stationary nucleus of mass M emits an electron of mass 'm' with a velocity 'v'. If the recoil velocity of the nucleus is V, the ratio of the de Broglie wave lengths of the nucleus and the electron is
Drift velocity is equal to
A body of mass m is moving in a circle of radius r with a constant speed υ. The force on the body is mυ2/r and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle
The work done is zero when the direction of the force is perpendicular to the direction of motion. Force is directed towards the center and the displacement, which means the shortest distance between two points is a straight line from one point of circle to another point over half the circumference.
Hence the angle formed between force and displacement is 90°.
An electron beam is subjected to perpendicular magnetic and electric fields of 5 x 10 − 4 w b m − 2 and 3 x 10 3 V m − 1 resectively. If there is no deflection, the velocity of electrons is
Since the path of electron remains undeviated, qvB=qE or
In a Wheatstone's bridge, all the four arms have equal resistance R. If resistance of the galvanometer arm is also R, then equivalent resistance of the combination is
A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m, then
When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface, then
For a given kinetic energy which of the following has the smallest de-Broglie wave-length ?
The effective value of a.c. in a circuit is 10 A. The peak value of current is
When light travels from air to water, which parameter does not change?
In an electromagnetic wave, the electric and magnetising fields are 100 Vm-1 and 0.265 Am-1. The maximum energy flow is
S = E0 x H0
E0 = 100 Vm-1, H0 = 0.265 Am-1
∴ S = 100 x 0.26 = 26.5 Wm-2
Three point charges -q, Q and -q are placed at equal distances on a straight line. If total potential energy of the system is zero, then the ratio of Q/q is
Figure shows a solid hemisphere with a charge of 5nC distributed uniformly through its volume. The hemisphere lies on a plane and point P is located on the plane, along a radial line from the centre of curvature at distance 15cm. The electric potential at point P due to the hemisphere is:
Two sphere of mass 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
The specific heats at constant pressure is greater than that of the same gas at constant volume because
A body is imparted motion from rest to move in a straight line. If it is then obstructed by an opposing force, then
Two parallel wires of length 9m each are separated by a distance of 0.15m. If they carry equal currents in the same direction and exert a total force of 30 x 10 − 7 N on each other, the value of current must be
A body takes T minutes to cool from 62°C to 61°C when the surrounding temperature is 30°C. The time taken by the body to cool from 46°C to 45.5°C is
According to Newton's law of cooling,
A vibration magnetometer is placed at South pole, then the time period will be
Which of the following materials is repelled by an external magnetic field?
If the radius of a soap bubble is four times that of another, then the ratio of their pressures will be
The extension in a string, obeying the Hooke's law, is x. The speed of sound in the stretched string is v. If the string is extended to 1.5 x, then speed of sound will be
Speed of sound in a stretched string
Where T is the tension in the string and μ is mass per unit length
According to Hooke's law, F ∝ x
If 200 Mev energy is released in the fission of a single nucleus of 92U235 , how many fissions must occur per second to produce a power of 1 kW?
The source of stellar energy is
A simple pendulum of length 'l' has a maximum angular displacement (θ). The energy of a bob of mass m at the end of the displacement is
In a Huygen's eye piece with an eyepiece of focal length F, the distance between the eye-piece and field lens should be
Rainbow is formed due to a combination of
If a gymnast, sitting on a rotating stool with his arms outstretched, suddenly lowers his hands
A body A of mass M while falling vertically downwards under gravity breaks into two parts, a part B of mass M/3 and body C of mass 2M/3. The centre of mass of the bodies B and C taken together
No horizontal external force is acting
∴ acm = 0
since vcm = 0
∴ Δxcm = 0
The half life of a radioactive material depends on
For a simple pendulum the graph between L and T will be
The band gap in Germanium and silicon in eV respectively is
In case of a semiconductor which of the following statement is wrong
Two 220 V, 100 W bulbs are connected first in series and then in parallel. Each time the combination is connected to 220 V ac supply line. The power drawn by the combination in each case respectively will be
When the temp. of a gas filled in a closed vessel is increased by 1°C, its pressure increases by 0.4 percent. the initial temperature of gas was
The physical quantities not having same dimensions are
A transverse wave is represented by the equation y = γ₀ sin 2 π/λ (V t - x) for what value of λ is the maximum particle velocity equal to two times the wave velocity?
Consider a car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of static friction between road and tyres is 0.5, the shortest distance in which the car can be stopped is
19g of water at 30°C and 5g of ice at − 20°C are mixed together in a calorimeter. What is the final temperature of the mixture ? Given specific heat of ice = 0.5 cal g − 1°C − 1 and latent heat of fusion of ice = 0.8 cal g−1
The quantities remaining constant in a collision are
Two similar sonometer wires given fundamental frequencies of 500 Hz. These have same tensions. By what amount the tension be increased in one wire so that the two wires produce 5 beats/sec
Two rectangular blocks A and B of masses 2kg and 3kg respectively are connected by a spring of spring constant 10.8Nm-1 and are placed on a frictionless horizontal surface. The block A was given an initial velocity of 0.15ms-1 in the direction shown in the figure. The maximum compression of the spring during the motion is
Which of the following has maximum hydrogen bonding?
Aldehydes and ketones do not give addition reaction with
Which of the following statements regarding spectral series is correct?
The relationship between the energy E₁ of the radiation with a wavelength 8000 Å and the energy E₂ of the radiation with a wavelength 16000 Å is
Haloalkane in the presence of alcoholic KOH undergoes
Which one of the following compounds in most acidic
The alcohol obtained by the hydrolysis of oils and fats is
In a reaction involving ring substitution of C6H5Y, the major product is meta isomer. The group Y can be
Electron withdrawing groups favour meta substitution
- COOH group is metadirecting group
Which of the following is not an amphoteric substance?
Which of the following is soluble in water?
The law of thermodynamics that provides the basis for the determination of absolute entropy of a substance is
The free energy change ΔG = 0,When
Which one of the following informations can be obtained on the basis of Le Chatelier principle ?
The plot of concentration of the reactant versus time for a reaction is a straight line with a negative slope. The reaction follows a
Consider the zero order reaction
R → P
Rate = d[R] / dt = k[R]∘
As any quantity raised to power zero is unity, we have
Rate = −d[R] / dt = k × 1
or d[R]=−kdt /
Integrating both rides
[R] = −kt + I.C
Where I.C. is the constant of integration.
At t = 0 the concentration of the reactant. R=[R]0, where
[R]0 is initial concentration of the reactant. Subtituting this result in the above equation, we get
[R]0=−k×0 + I.C
[R]0 = I.C
Comparing it with equation of a straight line, y=mx+c, if we plot [R] against t, we get a straight line with slope = - K are intercept equal to [R]0
For a reaction to occur spontaneously
A Carnot engine, working between 500 K to 300 K has a work output of 800 J-cycle⁻1. What is the amount of heat energy supplied to the engine from the source per cycle?
A broad spectrum antibiotic is
Chloramphenicol is a broad spectrum antibiotic . It is rapidly absorbed from the gastro intestinal tract.
Pencillin has a narrow spectrum and is effective only against diseases caused by various cocci and some gram positive bacteria.
Aspirin and Paracetamol are non additive analgesics.
IUPAC name of
Some salts although containing two different metallic elements give test for only one of them in solution. Such salts are
On passing 0.1 faraday of electricity through fused sodium chloride ,the amount of chlorine liberated is (At.mass of Cl = 35.45)
The standard e.m.f. of a galvanic cell, with standard electrode potentials of zinc equal to -0.76 V and that of copper equal to + 0.34 V, is
The e.m.f. of a cell prepared by combining Al/Al⁺3 and Ag/Ag⁺ is 2.46 V. The reduction potential of the silver electrode is +0.08 V. The reduction potential of the aluminum electrode is
The higher rate of heart disease in smokers is due to
In which of the following pairs, both the complexes show optical isomerism?
The product obtained on fusion of BaSO₄ and Na₂CO₃ is
Silver is present in
A container contains 1 mole of a gas at 1 atm pressure and 27°C, and its volume is 24.6 ltres. If pressure is 10 atm and temperature 327°C, then new volume is approximately
3.2 oxygen is diffused in 10 minutes. In similar conditions, 2.8 g nitrogen will diffuse in
The shape of gaseous SnCl₂ is
Cl₂ gas is dried over
If H⁺ ion conc. of a solution is increased by 10 times, its pH will
The indicator used in the titration of sodium carbonate with sulphuric acid is
Among the following, the weakest base is
Which is not the resonance structure of aniline?
Following carbocation changes to more stable carbocation :
The empirical formula of a compound is CH₂. One mole of compound has a mass of 42g, its molecular formula is
Which one of the following is not used for the purification of solid impurities?
Which of the following is not a reducing agent ?
Which of the following will have the highest F.P. at one atm?
A solution contains non-volatile solute of molecular mass M₂. which of the following can be used to calculate the molecules mass of solute in terms of osmotic pressure ?
Which one of the following is a colligative property?
Which of the following is not a property of hydrophilic sols?
The aqueous solution of the following salts will be coloured in the case of
Iron is extracted from magnetite by reduction with
Multicellular brached rhizoids and leafy gametophytes are the characteristics of
Frog's kidney is
Sugarcane plant has
Two distinct types of guard cells exist, kidney shaped and dumb-bell shaped. Kidney-shaped guard cells are found in dicotyledons whereas dumb-bell-shaped guard cells are found in grasses. Dumb-bell shaped guard cells are more advanced in evolutionary terms and more efﬁcient physiologically because guard cells of grasses require fewer solutes and less water to achieve a given unit increase in aperture.
The guard cells in monocot grasses, like sugarcane are dumbbell shaped.
In Funaria the antheridia and archegonia develop on the same plant but on separate branches. Thus Funaria is
Correct Answer :- none of these
Explanation : Funaria is monoecious and autoecious i.e., male and female reproductive structures develop on different branches of the same plant. Monoecious means both male and female sex organs are borne on the same plant body.
Part of spindle left after chromosomes have moved to poles is
The two chromatids of a metaphase chromosome represent
Which one controls movement of substances across cell membrane?
The golgi complex participates in
A plant cell has potential to develop into full plant. The property is called
Sunil's blood type was determined to be AB+. Which of the following is true of Sunil's blood?
Which blood cell can be described as being a biconcave disc?
Which type of condition is directly related to bone marrow suppression?
Which lipoprotein has the highest percentage of cholesterol?
LDL has the highest percentage of cholesterol plus cholesteryl esters
Causative agent of syphilis is :
In IVF technique, fusion of ovum and sperm occurs in :
Contraceptive oral pills help in birth control by :
Where does complete digestion of protein take place?
Digestion is brought about by
Number of individuals of a species in a particular ecosystem at a given time remains constant due to
Grasslands of Asia are
Herring bodies are found in
The organ which was considered vestigial till recently but now confirmed to be endocrine gland is
The word enzyme was coined by
Most abundant enzyme is
Chilgoza is the seed of -
In gymnosperms, ovules are
In E.coli, during lactose metabolism repressor binds to
Which one is incorrect
Mendel chose contrasting traits in Pea
The eye membrane which prevents the reflection of the extra light within the eye, by absorbing it is called
Immunity acquired after an infection is
AIDS was first reported in
An antiviral substance produced in response to viral infection for restricting its multiplication is
If Juvenile hormone is absent when silkworm moults. It will
Animals devoid of respiratory, excretory and circulatory organs are
Lichens are ecologically important as they
Bacteria can not survive in a highly salted pickle, because
Bacteria can prepare food from
Two fatty acid monomers are joined by
How many quanta of light are required to evolve one molecule of oxygen in photosynthesis ?
In C₄-plants, carbon dioxide combines with
Incomplete metamorphosis occurs in
A common feature of cockroach and housefly is that both have
In Pheretima, haemoglobin is present in
The female genital pore of Pheretima posthuma located upon the segment
Tunica Corpus theory was proposed by
Identify the correctly matched pair
Nearest to pod is
Transmission across a synapse is one-way because
Individuals of a species which occur in a particular area constitute
Edaphology is connected with
Which is correct pair bony fishes : stronger muscles ::
Brewer's yeast lack which of these
Transgenic animal has
An important example of serendipity is
Mycorrhiza is used in
Virus free plants can be obtained by
Modified antibiotics are manufactured by the technique of
Aneuploidy is commonly observed in different varieties of
Milk tastes sour when kept in the open for sometime due to formation of
Vessel elements differ from other elements of xylem in having
Photosynthates are transported through
The photosynthates from the source are usually translocated to the nearest sink through the phloem sieve tube elements. For example, the highest leaves will send sugars upward to the growing shoot tip, whereas lower leaves will direct sugars downward to the roots.
So, the correct answer is 'Sieve tubes.'
Respiration of Ascaris is
Positive pollution of soil is due to
DDT has been a major pollutant because it
Minamata disease was caused due to the consumption of
Hyperparasite is parasite which
An association of individuals of different species living in the same habitat and having functional interactions is
The constituent of natural silk is
Milky water of green coconuts is
In albuminous seeds the food is stored in
Embryo sac represents
Fruits having economically important pulp are propagated vegetatively because
Which of the following store sperm cells and eliminate those that have major genetic defects?
The corpus luteum is formed at the site of
Low levels of estrogen and progesterone in the blood will result in
Inferior ovary with cypsella fruits are found in the family-