Reactance of a capacitor of capacitance CμF for A.C. frequency 400/μ Hz is 25Ω. The value C is
An electric wire of length 'l' and area of cross section a has a resistance R ohms. Another wire of the same material having same length and area of cross-section 4a has a resistance of
The angular velocity of the minutes hand of a watch is—
The closest distance of approach of an α- particle travelling with a velocity 'V' to a certain nucleus is 'x'. The distance of closest approach of α- particle travelling with a velocity 3V to the same nucleus is
A voltmeter having a resistance of 998 ohms is connected to a cell of e.m.f. 2 volt and internal resistance 2 ohm. The error in the measurement of e.m.f. will be
The space between the plates of a parallel plate capacitor is filled consecutively with two dielectric layers of thickness d1 and d2 having relative permittivities ε1 and ε2 respectively. If A is area of each plate, the capacity of the capacitor is
An electromagnet has stored 648 J of energy, when a current of 9 A exists in its coils. If the current is reduced to zero in 0.3 s, then average induced e.m.f. in the coils is
The capacitance of a parallel plate capacitor becomes 4/3 times its original value if a dielectric slab of thickness t = d/2 is inserted between the plates (where d is separation between the plates). The dielectric constant of the slab is
The velocity of electromagnetic wave is parallel to
During a current change from 2 A to 4 A in 0.05 second, 8 V of emf is developed in a coil. the coefficient of self-induction is
An infinite no. of capacitors with capacitances 1μF, 1/21μF, 1/41μF, 1/81μF, ...etc. are connected in parallel combination. Their equivalent capcitance will be
A block weighs w is held against a vertical wall by applying a horizontal force f. The minimum value of F needed to hold the block is
If the value of g at the surface of the earth is 9.8 m/sec2, then the value of g at a place 480 km above the surface of the earth will be
A mass M is split into two parts m and (M - m), which are then separated by a certain distance. The ratio m/M , which maximizes the force of attraction between the two parts is
If the temperature of the sun is doubled, the rate of energy received on earth will be increased by a factor of
Mean free path of a gas molecule is :
If distance between the slits of Young's double slit experiment is reduced to half, then the fringe width will
A galvanometer can be changed into an ammeter by using
A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
A uniform magnetic field acts at right angle to the direction of motion of electron. As a result of this, the electron describes a circular path of radius 2 cm. If speed of electron is doubled, then radius of circular path will become
A magnet of length 10cm and magnetic moment 1 Am2 is placed along the side AB of an equilateral triangle ABC. If the length of the side AB is 10cm, the magnetic induction at the point 'C' is ( μ0 = 4π × 10−7 Hm−1 )
Isogonic lines are those for which
An incompressible fluid flows steadily through a cylindrical pipe which has radius 2 R at point A and radius R at point B. If velocity at point A is ν, then its velocity at point B is
Most of the sustances show which of the magnetic property :
The shape of liquid meniscus in capillary tube will be concave upwards, if the angle of contact is
A wire can be broken by applying a load of 200 N.The force required to break another wire of the same length and same material, but double in diameter, is
A car drives along straight level frictionless road by an engine delivering constant power. Then velocity is directly propotional to
Moment of inertia along the diameter of a ring is
A radio active sample has a half life of 5 days. To decay from 8 micro curies to 1 micro-curie, the number of days taken will be
The decay constant of a radio active substance is λ . Its half life is
Swimming is possible on account of
The magnifying power of eye piece in a compound microscope is 5 and the combined magnifying power is 100. The magnifying power of objective lens is
The length of simple pendulum executing SHM is increased by 21%. The percentage increase in the time period of the pendulum of increased length is
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
Why sun elliptical shape when it rises and sets ? It is due to
A ball is projected with kinetic energy E at an angle of 45º to the horizontal. At the highest point during its flight, its kinetic energy will be
When ultraviolet rays are incident on metal plate then photoelectric effect does not occur, it occurs by incidence of
The ultraviolet region of the spectrum was first detected by
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
Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of this lens when immersed in a liquid of refractive index of 1.25 will be
The angular speed of a fly wheel making 120 rpm 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'm' is tied to one end of a spring and whirled round in a horizontal plane with a constant angular velocity. The elongation in the spring is one centimeter. If the angular velocity is doubled, the elongation in the string is 5cm. The original length of the spring is
Electronic configuration of germanium is 2, 8, 18 and 4. To make it extrinsic semiconductor small quantity of antinomy is added
The band gap in germanium and silicon in eV respectively is
To hear an echo, the reflecting surface must be at a minimum distance of
To hear the echo distinctly, the time gap between the two sounds must be 0.1 s.
Let the distance between the listener and the reflecting surface be d
The total distance travelled by the sound = 2d
Thus the minimum distance between the listener and the reflecting surface to hear the echo in air is 16.5 m (when the velocity of sound through air is 330 ms-1)
Due to capillary action a liquid will rise in a tube if the angle of contact is
Heat produced in a conductor of resistance R, when a current of I amperes flows through it for t seconds, is given by
Electric bulb 50 W-100 V glowing at full power are to be used in parallel with battery 120 V, 10Ω. Maximum number of bulbs that can be connected so that they glow in full power is
If 96500 coulombs of electricity liberates one gram equivalent of any substance, the time taken for a current of 0.15 amperes to deposite 20mg of copper from a solution of copper sulphate is (Chemical equivalent of copper =32)
Equivalent weight of copper = 32
Charge required to deposit 32 g = 96500 C
Charge required to deposit 20 x 10-3 g,
The pressure and temperature of an ideal gas in a closed vessel are 720 KPa and 40º C respectively. If 1/4 th of the gas is released from the vessel and the temperature of the remaining gas is raised to 353º C , the final pressure of the gas is
110 J of heat is added to a gaseous system, whose internal energy change is 40 J, then the amount of external work done is
In the P-V diagram shown in figure, the work done will be
One yard in SI unit is equal to
The units of angular momentum are
The superposition principle applies to
Two sources of same intensity interfere at a point and produced resultant I. When one source is removed, the intensity at that point will be
Suppose that the speed of sound in air at a given temperature is 400 m/sec. An engine blows a whistle at 1200 Hz frequency. It is approaching an observer at the speed of 100 m/sec. What is the apparent frequency as heard by the observer
In transverse wave the oscillations are
A body of mass 10 kg is dropped to the ground from a height of 10 mts. The work done by the gravitational force is (g = 9.8 m/sec2)
Chloroform, on heating with zinc dust and water, forms
When Cl₂ is passed through propene at 400ºC. Which of the following is major product ?
In its reaction with silver nitrate acetylene shows
A pale green crystalline metal salt of M dissolves freely in water. It gives a brown precipitate on addition of aqueous NaOH. The metal salt solution also gives a black precipitate on bubbling H₂S in aqueous memdium. An aqueous solution of the metal salt decolourizes the pink colour of the permanganate solution. The metal in the metal salt solution is
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 maximum number of electrons in a subshell is given by the expression
Which of the following explains the sequence of filling electrons in different subshells?
The atoms of different elements, having same number of neutrons, but different mass numbers and atomic numbers, are called
The alkyl halide is converted into ethyl alcohol by
According to VSEPR theory, the shape of the water molecule is
Which of the following statement is not correct for sigma and pi bonds formed between two carbon atoms
(ΔH - ΔU) for formation of carbon monoxide (CO) from its elements at 298 K is (R = 8.314 KJ-1 mol-1)
For the following three reactions a, b and c, equilibrium constants are given :
Which of the following relations is correct?
The half life of a reaction is found to be inversely proportional to the cube of its initial concentration of the reactants. The order of the reaction is
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?
The heat of formation of CO and CO₂ are -26.4 kcal and -94.0 kcal respectively . Heat of combustion of carbon monoxide will be
The compound formed on heating chlorobenzene with chloral in the presence of concentrated sulphuric acid is
How many carbon atoms in the molecules HOOC-(CHOH)₂ - COOH are asymmetric ?
Among [Ni(CO)4], [Ni(CN)4]2- and [NiCN4]2- species, hybridisation states at Ni atom (At. no. of Ni = 28) are respectively
(1) In [Ni(CO)4], Nickel is in "zero' oxidation state and it shows sp3 hybridisation
So this complex is Tetrahedral
(2) [NiCl4]2- is paramagnetic and Tetrahedral
(3) [Ni(CN)4]2- is diamagnetic and square planer
In [Ni(CN)4]2- ion, nickel is in +2 oxidation state
Ni atom in ground state
(Atomic number = 28)
As hybridisation in dsp2, so given complex is square planer
Which of the following is not isoelectronic?
Isoelectronic species: a group of ions, atoms, or molecules that have the same number of electrons.
Number of electrons in Na+ = 10
Number of electrons in Mg2+ = 10
Number of electrons in O2 − = 10
Number of electrons in Cl − = 18
HNO₂ acts both as reductant and oxidant, while HNO₃ acts only as oxidant. It is due to their
Calcium is obtained by the
The metal used for making radiation shield is
Air at sea level is dense. This is a practical application of
Which of the following is not correct?
Which of the following mixture of gases does not obey Dalton's law of partial pressure ?
Which one of these is basic?
Galena is an ore of
Which one of the following statements is correct for alkaline earth metals?
The bond energies of F₂, Cl₂, Br₂ and I₂ are 155, 244, 193 and 151 kJ mol⁻1 respectively. The weakest bond will be in
Water is said to be permanently hard when it contains
Which has maximum number of oxo groups?
At 25ºC, the value of a solution is 6. The solution is
Phosphine is prepared by the action of
The strongest Bronsted base in the following anion is
when HCl gas is passed through a saturated Solutions of NaCl , the solubility of Nacl:
Radioactive disintegration differs from a chemical change in being
The racemix mixtures in which constituents are crystalline and have distinct difference in their shape, is separated by which of the following method?
Given below are some statements concerning formic acid, which of them is true ?
A cyclotron can not accelerate
Which gives more stable product ?
following step is :
Alkene RCH═CH₂ reacts readily with B₂H₆ and the product on oxidation with alkaline hydrogen peroxides gives
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
Hydrolysis of trichloromethane with aqueous KOH gives
Ethyl bromide reacts with lead-sodium alloy to form
When NaCl is dissolved in water, the sodium ion becomes
The catalyst used for the polymerization of olefins is
Impure glycerine is purified by
The oxidation states of phosphorous vary from
Which of the following has square planar structure?
Electrophilic substitution in phenol generally occurs at
The molal freezing point constant for water is 1.86ºC/mole. If 342 gm of cane sugar (C₁₂H₂₂O₁₁) is dissolved in 1000 g of water, the solution will freeze at
The extent of adsorption of a gas on a solid depends on
Molar solution is one that
Piezoelectric crystals are used in
The optical isomerism is shown by :
What is the volume (in litres) of oxygen at STP required for complete combustion of 32 grams of CH4?
Cuprous ion is colourless while cupric ion is coloured because
Nessler's reagent is
Recombination nodules are found during
The free larval stage can be traced in one of the following sets
The atrioventricular (AV) node stimulates the
Nematocysts of Hydra are important for:
Which of these is a water soluble vitamin?
Central Tobacco Research Institute is situated at
Together, leukocytes and platelets comprise approximately _____ percent of total blood volume.
Which chemical initiates the extrinsic phase of clotting?
Which two enzymes break down the same substrate?
A drug from root which causes mental disorder and reduces blood pressure is obtained from
Energy enters into the ecosystem through
Gasohol is a mixture of
Rubber is collected from
Pyramid of energy (in a forest ecosystem) is
Coriandrum sativum is the botanical name of
Pollinia are found in which of the following plant family ?
Which of the following hormones is steroid?
Hormone connected with concentration of urine or reabsorption of water by nephron is
DNA segment, 3' TAC ATG GGT CCG 5', transcribes one mRNA. Four tRNA with anticodons (a) AUG (b) UAC (c) CCG and (d) GGU are required for translation. What is the order of tRNAs.
Food chains operate in
Which of the following is an inherited disorder ?
Mendel's first law in often called
Ductus reuniens connects
A colour blind person can not distinguish
Which of the following is the largest ear ossicle ?
Individuals of the same species inhabiting a particular locality constitute
Ploidy of microspore is
Trochophore larva belongs to
The lymphatic trunk that drains the upper limb is the _______________.
Aristotle's lantern occurs in class
An essential element is that which
What is one major force that causes interstitial fluid to enter lymphatic capillaries?
If the stem grows towards sunlight and root grows just opposite to it, the stem movement is called
The classical experiments in growth were performed by
The kingdoms-monera, protista, fungi, plantae and animalia are distinguished on the basis of
Wildlife is destroyed most when
An essential process connected with photosynthesis is
Body of sponges in mainly composed of
Which one of the following substances plays an important role in biochemical defence of host plants?
In which one of the following pathogens do the cells of promycelium after the germination of teleutospore produce infection hyphae instead of basidiospores?
Which among the following is the man made cereal?
In acid rain, sulphuric acid accounts for
Aerosols decrease primary productivity by
Upon fertilisation while ovule develops into seed, which structure develops from a carpel
End products of aerobic respiration are
Which of the following biological processes is faster in human males than in human females?
In what form is most of the carbon dioxide (CO2) transported in the blood?
Which of the following pair has haploid structures
For two molecules of glucose, glycolysis uses and produces ATP molecules
Bull Frog of India is
Potatoes develop on
"Osmosis is flow of solution from higher concentration to solution of lower concentration through semi-permeable membrane." Which is incorrect in the statement ?
Plants are mainly divided into two groups according to Bentham and Hooker, these are -
The component units of compound eye of Cockroach are called
The correct sequence of structures through which air passes during inhalation is
Which substance would normally be found in higher concentration in urine than in blood?