Voltage and current in an A.C. circuit are given by V = 5 sin(100πt - π/6) and I = 4sin(100πt + π/6)
An electron remains undeflected when passing perpendicular to mutually perpendicular electric and magnetic fields. If the magnetic field is 8 Gauss and elecric field is 4000 V/m, the velocity of the electron is
A parallel plate capacitor of plate area A and the plate separation d is charged to potential difference V and then the battery is disconnected. A slab of dielectric constant K is then inserted between the plates of the capacitor so as to fill the space between the plates. If Q, E and W denote respectively, the magnitude of charge on each plate, the electric field between the plates and work done by the system in question, in the process of inserting the slab, then select the incorrect relation from the following :
The average acceleration vector for a particle having a uniform circular motion is
The length of a wire of a potentiometer is 100 cm, and the e.m.f. of its standard cell is E volt. It is employed to measure the e.m.f. of a battery, whose internal resistance is 0.5 Ω. If the balance point is obtained at l = 30 cm from the positive end, the e.m.f. of the battery is
Which of the following radiations have the least wavelength?
In a circuit, n identical bulbs, each of power 'P' are joined in series across a power supply. The total power drawn by the bulbs is
A 220 V, 1000 watt bulb is connected across a 110 V mains supply. The power consumed will be
A 12 Ω resistor and a 0.21 henry inductor are connected in series to an AC source operating at 20 volt, 50 cycle. The phase angle between the current and the source voltage is
A parallel plate air condenser has certain capacity. When 2/3 of the distance between the plates is filled with a dielectric, the capacity is found to increase by a factor of 2.25. The dielectric constant 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:
A brick of mass 2 kg beings to slide down on a plane inclined at an angle of 45º with the horizontal. The force of friction will be
If acceleration due to gravity on the earth's surface is g, then value of acceleration due to gravity at a height of 32 km above the earth's surface is
Mud houses are cooler in summer and warmer in winter because
Two particles of eqaul mass go round a circle of radius R under the action of their mutual gravitational attration. The speed of each particle is
In two separate setups of the Young's double slit experiment, fringe of equal width are observed when lights of wavelengths in the ratio 1:2 are used. If the ratio of the slit separation in two cases is 2:1, the ratio of distances, between the plane of slits and the screen, in the two setups is
Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will
An electrical meter of internal resistance 20 Ω gives a full scale deflection when one milliampere current flows through it. The maximum current, that can be measured by using three resistors of resistance 12 Ω each, in milliamperes is
The magnetic field of given length of wire for single turn coil at its centre is B, then its value for two turns coil for the same wire is
Cathode rays and canal rays produced in a certain discharge tube are deflected in the same direction, if
In discharge tube cathode rays (a beam of negative particles ) and canal rays (positive rays) moves opposite to each other.
They will experience a magnetic force in the same direction, if a normal magnetic field is switched on.
The null points are on the axial line of a bar magnet, when it is placed such that its south pole points
A magnetised wire of magnetic moment M is bent into an arc of a circle that subtend and an angle of 60º at the centre. The equivalent magnetic moment is
The material for which susceptibility remains constant for small values of magnetising field, increases for large values and then decreases for very large values is
An air bubble of radius 10 mm is rising at a steady rate of 8 mm-s⁻1 through a liquid of density 1.47x103 kg-m⁻3. Neglecting density of air, the coefficient of viscosity of the liquid is (Take g = 9.8 m-s2)
In a liquid flowing through a pipe, the pressure difference between its ends is made half and radius is doubled. If the initial rate of flow of liquid was Q, then new rate of flow of liquid through the pipe 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
A constant torque of 1000 N-m turns a wheel of moment of inertia 200 kg-m2 about an axis through its centre. Its angular velocity after 3 sec is
A man is at rest in the middle of a pond on perfectly smooth ice. He can get himself to the shore by making use of Newton's
A constant acts on a body of mass 0.9 kg at rest for 10 s. If the body moves a distance of 250 m, the magnitude of the force is
Two lithium nuclei in a lithium vapour at room temperature do not combine to form a carbon nucleus because
Why high temperature is required for fusion reaction?
The magnifying power of a telescope is 'm'. If the focal length of the eye piece is doubled, then its magnifying power will become
If the metal bob of a simple pendulum is replaced by a wooden bob, then its time period will
For photoelectric emission to take place
The electrons are emitted in the photoelectric effect from a metal surface
Two projectiles are fired from the same point with the same speed at angles of projection 60º and 30º respectively. Which one of the following is true?
In order to increase the angular magnification of a simple microscope, one should increase
If the dispersive power of a lens material of focal length 20 cm is 0.08, then longitudinal chromatic aberration of the lens is
A luminous object is placed at a distance of 30 cm from the convex lens of focal length 20 cm. On the other side of the lens, at what distance from the lens a convex mirror of radius of curvature 10 cm be placed in order to have an inverted image of the object coincident with it ?
The apparent depth of water in cylindrical tank of diameter 2R is reducing at the rate of x per min, when water is being drained at a constant rate. The amount of water drained per min is (μ₁ = Refractive index of air; μ₂=Refractive index of water)
When a sphere of moment of inertia I about its centre of gravity and mass 'm' rolls from rest down an inclined plane without slipping, its kinetic energy is
A particle is moving in a circle with uniform speed. Its motion is
The kinetic energy and potential energy of a particle executing simple harmonic motion will be equal, when displacement (amplitude = a) is
Semiconductor is damaged by the strong current due to
The bond that exists in a semiconductor is
A string of a musical instrument is 50 cm long and fundamental frequency is 270 Hz. If the desired frequency of 1000Hz is to be produced, the required string length is
A square frame of side L is dipped in a liquid. On taking out, a membrane is formed.If the surface tension of the liquid is T, the force acting on the frame will be
Heat produced in a conductor of resistance R, when a current of I amperes flows through it for t seconds, is given by
A current of 2 A passing through conductor produces 80 J of heat in 10 seconds. The resistance of the conductor is
Two identical wires of resistance R are first connected in series and then in parallel. The amount of heat produced in both the conditions are in the ratio of
A cylinder contained 10 kg of gas at 107 N/m2. The quantity of gas taken out of cylinder if final pressure is 2.5 x 106N ∕ m2 is (temp. is constant)
If Q,E and W denote respectively the heat added, change in internal energy and the work done in a closed cycle process, then
The adiabatic Bulk modulus of a perfect gas at pressure P is given by
Which of the following pair is wrongly matched?
The dimensional formula for impulse is
When light wave suffer reflection at the interface between air and glass, the change of phase of reflected wave is equal to
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
Who was the first to demonstrate the phenomenon of interference of light?
A source of sound and listener are approaching each other with a speed of 40 m/s. The apparent frequency of note produced by the source is 400 CPS. Then, its true frequency (in CPS) is (velocity of sound in air = 360 m/s)
The potential energy of a body given by : A - Bx2. The magnitude of force acting on the particle is
Hydrolysis of NCl3 gives NH3 and x. Which of the following is x ?
The reagent used for converting acetylene to oxalic acid is
Which of the following with aqueous KOH will give acetaldehyde ?
In its reaction with silver nitrate acetylene shows
According to which of the following rule, nitrogen atom, has three unpaired electrons?
Which of the following is not precipitated as sulphide by passing H₂S in the presence of conc. HCl?
An electron has a apin quantum number + 1/2 and a magnetic quantum number -1. It cannot be present in
Which of the following orbitals have a dumb bell shape?
Among the following the electron deficient compound is
Which of the following alkyl group has the maximum + I effect?
Element X of group V-A combines with element Y of group VI-A. The probable formula of the compound is
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
1 mole of N₂ and 2 moles of H₂ are allowed to react in a 1 dm3 vessel. At equilibrium 0.8 mole of NH₃ is formed. The concentration of H₂ in the vessel is
A foreign substance, that increases the rate of reaction, is called
Given the bond energies of N ≡ N , H − H and N − H bonds as 941.5, 433 and 391 kJ mole-1 respectively, the enthalpy of reaction N2(g) + 3H2g → 2NH3(g) is
Enthalpy of reaction = ∑ bond energyreactant - ∑ bond energyproduct
= bond energy (n2) + 3 x (bond energy) (h2) - 2 x (bond energy) (NH3)
= 941.5 + (3 x 433) - 2 x 3 x 391
= 2240.5 - 2346 = 105.4 ≅ -105kJ
Mechanical work is specially important in systems that contain
Medicine which is an antibiotic is
Which is the most stable carbocation ?
Which one of the following elements has the highest first ionisation potential
As we move across a period from left to right, the nuclear charge increases and the atomic radius decreases though the principal quantum number of the valence shell remains the same. As a result, the valence electrons are more are more tightly held by the nucleus, hence ionisation potential keep on increasing. However, N show extra-stability of the exactly half-filled electronic configuration, hence show higher ionisation potential than oxygen.
Electronic configuration of N:
The oxidation state of Fe in brown complex [Fe(H₂O)₅NO]SO₄ is
Which one of the following reactions is an example for calcination process?
If the four tubes of a car are filled to the same pressure with N₂,O₂,H₂ and Ne separately, then which one will be filled first ?
In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam. The reason for this is
In electrolysis of NaCl when Pt electrode is taken then H2 liberated at cathode while with Hg cathode it forms sodium amalgam because more voltage is required to reduce H+ at Hg than Pt
Density ratio of O₂ and H₂ is 16 : 1. The ratio of its V rms is
Action pf caustic soda on aluminium hydroxide gives a compound having formula
The decreasing order of second ionization potential K, Ca and Ba is
The oxidation number of S in H₂S₂O₈ is
Which has the highest molar heat of vapourization?
When oxalic acid is dehydrated by conc. H₂SO₄, then it forms
The alcohol manufactured from water gas is
Which of the following reagents is used to distinguish between methanoic acid and ethanoic acid ?
Which of the following will show geometrical isomerism?
It is found that 0.1 m solution of four sodium salts NaA,NaB and NaD have the following pH values :
Which one of the corresponding acids is strongest ?
Choose the solution with lowest pH value
Which one of the following is explosive and readily hydrolysed?
Buffer solution can be obtained by mixing aqueous solution of
Correct increasing order of acidity is as follows:
When ethylamine is heated with chloroform and alcoholic KOH, a compound with offensive smell is obtained. This compound is
When benzenediazonium chloride is treated with water, the compound formed is
A human body required 0.01 μC activity of radioactive substance for 24 hrs. Half life of radioactive substance is 6 hours. Then injection of maximum activity of radioactive substance (in μC) can be injected is
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
Which of the following fissionable material is used in nuclear reactor as fuel?
Electrophilic substitution in phenol generally occurs at
A dibasic acid containing C, H and O was found to contain C = 26.7% and H = 2.2%. The vapour density of diethyl ester was found to be 73. What is Molecular formula of acid?
Conc. HNO3 forms NO2+ in presence of :
Which does not contain conjugated system?
In dienes, when the double bonds connected to each other by a single bond, this arrangement is known as conjugated.
Which of the following is used for making seat covers and carpet fibres?
The colour of CoCl₃.5NH₃.H₂O is
Ionic solids with Schottky defects contain in their structure
When 15 g of solute was dissolved in water, it produced a depression of 1.2ºC in its freezing point. If molecular weight of the solute is 154.2, then weight of water in the solution is (K for water is 1.85 K-kg⁻1)
Of the following compounds, which will have zero dipole moment?
The process in which oxidation number increases is known as
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
A solution contains a non-volatile solute. Which of the following can be used to calculate molecular weight (M) of the solute in terms of osmotic pressure? (m=Weight of solute, V=volume of solution and π = Osmotic pressure)
The number of ions formed on dissolving one molecule of FeSO₄ (NH₄)₂SO₄. 6H₂O is/are
Adsorption is a phenomenon, in which a substance
Super conductors are derived from compounds of
If 0.5g of metal on oxidation formed 0.79 g of its oxide, then equivalent weight of the metal is
Vector of yellow fever is:
The highest blood pressure in the aorta occurs when the
Portugese man of war is the common name of
Spindle fibres are attached to chromosomes in the region of
Activities of the digestive system are generally increased by _________________ nervous stimulation.
Which of these can dissolve a blood clot?
The buffy coat evidenced by separating blood cells is comprised of _____.
Which of the following acts to inhibit acid production?
An aquatic fern used as bio-fertilizer is
Nutmegs of commerce which is extensively used as spices belong to genus
Quinine is obtained from
In which part of the body, honey bee keeps the nectar for sometime?
Cauliflower, used as vegetable is
Which of the following is dissolved in water for making Bordeaux mixture?
A mineralocorticoid is
The sphere of living matter together with water, air and soil on earth's surface is called
Who proposed the term ecosystem ?
Zona glomerulosa or glomerular area of adrenal cortex is involved in
Biome with broad-leaved resinous fire resistant drought enduring plants is
Protein cover of virus is
An externally observable characters of an individual are called
Presence of extra finger or toe is known as
In angiosperm, all 4 microspores of tetrad are covered by a layer which is formed by
Which one of the following conditions though harmful in itself, is also a potential saviour from a mosquito borne infectious disease ?
Loss of forests, urbanization, increasing pollution are all due to
J-growth curve has
Sensory neurons of retina of eye are
Between the osseous and membranous labyrinths is present a fluid called
Nutrition in sponges in
Which of the following is not an area that contains lymph nodes?
Echolocation is trait of
What is the main cause of edema following damage to an area of lymphatic vessels?
An essential element is that which
Biomass produced by plants in oceans accounts for
Protoplasmic streaming theory of translocation of organic solutes was first proposed by
The percentage of light energy utilised for photosynthesis by higher plants is
The term species was coined by
Devil fish is common name of
Which one of the following substances plays an important role in biochemical defence of host plants?
When the dark period of short day plants is interrupted by a brief exposure of light the plant
Most abundant water pollutant is
Movements of tendrils in response to sensation of touch is
The accidental discovery of antibiotics by Alexander Flemming was made in the year
Nitrogen fixation occurs in
Pollination by insect is
Graffian follicle are characteristically found in the
Fluoride pollution mainly affects
RQ is less than one for
In porifera, skeleton forming cells are
An anther having four microsporocytes shall produce pollen grains
The first four-carbon compound formed in Krebs cycle is
The level of CO2 in the blood is monitored by the
There is a stem modification in Ruscus. It is
The process of inhaling is accomplished in part by
Chloragogen cells are present in
Which one will excrete silicates consumed by Earthworm alongwith food
Find the Antonym of HOST
Androecium in Malvaceae is -
Which of the following structures would not be considered an organ of excretion?