A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by
Dimensions of resistance in an electrical circuit, in terms of dimension of mass M, of length L, of time T and of current I, would be
When you make ice cubes, the entropy of water
The fossil bone has a 14C : 12C ratio, which is [1/16] of that in a living animal bone. If the half-life of 14C is 5730 years, then the age of the fossil bone is
Mass spectrometric analysis of potassium and argon atoms in a Moon rock sample shows that the ratio of the number of (stable) 40Ar atoms present to the number of (radioactive) 40K atoms is 10.3. Assume that all the argon atoms were produced by the decay of potassium atoms, with a half-life of 1.25 x 10 9 yr . How old is the rock?
The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic fluxф linked with the primary coil is given bфy = ф 0 + 4t , where ф is in weber, t is time in second andф 0 is a constant, the output voltage across the secondary coil is
A beam of electrons passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move
Two parallel large thin metal sheets have equal surface charge densities (σ = 26.4 x 10 -12 C/m2 ) of opposite signs. The electric field between these sheets is
In the figure a proton moves a distance d in a uniform elecreic field as shown in the figure. Does the electric field do a positive or negative work on the proton? Does the electric potential energy of the proton increase or decrease?
Which one of the following is a possible nuclear reaction?
Two radioactive substances A and B have decay constants 5λ and λ respectively. At t = 0 they have the same number of nuclei. The ratio of number of nuclei of A to those of B will be (1/e) 2 after a time interval
A particle is thrown above, then correct v-t graph will be
The phase difference between the instantaneous velocity and acceleration of a particle executing simple harmonic motion is
The figure shows three circuits with identical batteries, inductors and resistance. Rank the circuits according to the currents through the battery just after the switch is closed, greatest first.
A bimetallic strip consists of metals X and Y. It is mounted rigidly at the base as shown. The metal X has a higher coefficient of expansion compared to that for metal Y. When bimetallic strip is placed in a cold bath
A wire mesh consisting of very small squares is viewed at a distance of 8 cm through a magnifying converging lens of focal length 10 cm, kept close to the eye. The magnification produced by the lens is
An asteroid of mass m is approaching earth, initially at a distance of 10 Re with speed vi . It hits the earth with a speed vf (Re and Me are radius and mass of earth), then
A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distance of 2 m and 3 m respectively from the source. The ratio of the intensities of the waves at P and Q is
A beam of parallel rays is brought to focus by a plano-convex lens. A thin concave lens of the same focal length is joined to the first lens. The effect of this is
In photoelectric effect, the electrons are ejected from metals if the incident light has a certain minimum
Identify the wrong description of the below figures
A lens is made of flint glass (refractive index = 1.5). When the lens is immersed in a liquid of refractive index 1.25, the focal length :
By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg (density = 13.6 g/cm3 ). Using the straw, he can drink water from a glass upto a maximum depth of
A ray of light is incident on the surface of a glass plate of thickness t. If the angle of incidence θ is small, the emerging ray would be displaced side ways by an amount [Take n = refractive index of glass)
For inelastic collision between two spherical rigid bodies
Two spheres of same size, one of mass 2 kg and another of Mass 4 kg, are dropped simultaneously from the top of Qutab Minar (height = 72 m). When they are 1 m above the ground, the two spheres have the same
A person used force (F), shown in figure to move a load with constant velocity on given surface.
Identify the correct surface profile
A particle starting from the origin (0, 0) moves in a straight line in the (x, y) plane. Its coordinates at a later time are (√3, 3). The path of the particle makes with the x-axis an angle of
If alpha, beta and gamma rays carry same momentum, which has the longest wavelength?
Flash light equipped with a new set of batteries, produces bright white light. As the batteries wear out
The moment of inertia of a rod about an axis through its centre and perpendicular to it is (1/12)ML 2 (where M is the mass and L, the length of the rod). The rod is bent in the middle so that the two halves make an angle of 60°. The moment of inertia of the bent rod about the same axis would be :
A mass of 2.0 kg is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released the mass executes a simple harmonic motion. The spring constant is 200 N/m. What should be the minimum amplitude of the motion, so that the mass gets detached from the pan? (Take g =10 m/s 2 )
When a body falls in air, the resistance of air depends to a great extent on the shape of the body. Three different shapes are given. Identify the combination of air resistances which truly represents the physical situation ?(The cross-sectional areas are the same)
The resistance of an ammeter is 13 Ω and its scale is graduated for a current upto 100 A. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto 750 A by this meter. The value of shunt resistance is
A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is
The minimum potential difference between the base and emitter required to switch a silicon transistor 'ON' is approximately
Specific rotation of sugar solution is 0.01 SI units. 200 kg-m-3 of impure sugar solution is taken in a polarimeter tube of length 0.25 m and an optical rotation of 0.4 rad is observed. The percentage of purity of sugar in the sample is
A boat at anchor is rocked by waves whose crests are 100 m apart and velocity is 25 m/s. The boat bounces up once in every
The figure shows the path of a positively charged particle 1 through a rectangular region of uniform electric field as shown in the figure. What is the direction of electric field and the direction of deflection of particles 2, 3 and 4?
We have seen that a gamma-ray dose of 3 Gy is lethal to half the people exposed to it. If the equivalent energy were absorbed as heat, what rise in body temperature would result?
Two tuning forks P and Q when set vibrating, give 4 beats /s. If a prong of the fork P is filed, the beats are reduced to 2 /s. What is frequency of P, if that of Q is 250 Hz ?
238U92 has 92 protons and 238 nucleons. It decays by emitting an alpha particle and becomes
The spatial distribution of the electric field due to charges (A, B) is shown in figure. Which one of the following statements is correct?
The speed (v) of ripples on the surface of water depends on surface tensioσn)(density (ρ) and wavelength (λ). The square of speed (v) is proportional to
In radioactive decay process, the negatively charged emitted β-particles are
A beam of 35.0 keV electrons strikes a molybdenum target, generating the X-rays. What is the cutoff wavelength?
A particle executes simple harmonic oscillation with an amplitude a. The period of oscillation is T. The minimum time taken by the particle to travel half of the amplitude from the equilibrium position is
The voltage of clouds is 4 x 10 6 V with respect to ground. In a lightning strike lasting 100 ms, a charge of 4 C is delivered to the ground. The power of lightning strike is
If the cold junction of a thermocouple is kept at 0°C and the hot junction is kept at T °C then the relation between neutral temperature (Tn) and temperature of inversion (Ti) is
In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an
A particle of mass m moves in the XY plane with a velocity v along the straight line AB. If the angular momentum of the particle with respect to origin O is LA when it is at A and LB when it is at B, then
The figure below shows the plot of (pV/nT) versus p for oxygen gas at two aifferent temperatures
Read the following statements concerning the above curves (i) The dotted line corresponds to the 'ideal' gas behaviour (ii) T1 > T2 (iii) The value of (pV/nT) at the point where the curves meet on they-axis is the same for all gases. Which of the above statements is true?
A leaf which contains only green pigments, is illuminated by a laser light of wavelength 0.6328 µm. It would appear to be
Hard X-rays for the study of fractures in bones should have a minimum wavelength of 10 - 11 m. The accelerating voltage for electrons in X-ray machine should be
A six pole generator with fixed field excitation developer an emf of 100 V, when operating at 1500 rpm. At what speed must it rotate to develop 120 V?
Energy from the sun is received on earth at the rate of 2 cal per cm2 per min. If average wavelength of solar light be taken at 5500 Ǻ then how many photons are received on the earth per cm2 per min? (h = 6.6 x 10 -34 J-s 1 cal = 4.2 J)
A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of
When a p-n junction diode is reverse biased, then
An amplifier has a voltage gain Av = 1000. The voltage gain in dB is :
A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C, then the resultant capacitance is
What is the amount of urea dissolved per litre if its aqueous solution is isotonic with 10% cane sugar solution? (mol. wt. of urea = 60)
Synthetic petrol is prepared by
Aniline reacts with......to yield ....... as the final product.
Which of the following is correct?
Which of the following has lowest boiling point?
The values of four quantum numbers of valence electron of an element are and s = + 1/2. The element is
A compound X undergoes reduction with LiAlH4 to yield Y. When vapours of Y are passed over freshly reduced copper at 300°C, X is formed. What is Y?
The rate of chemical reaction doubles for every 10°C increase in temperature, if the temperature of reaction is increased from 30°C to 80°C. The rate of reaction increases
Wet ether is not used as a solvent in Wurtz reaction, because the water present in it
The, most probable velocity (in cm/s) of hydrogen molecule at 27°C, will be
The absolute configuration of the following are :
The total number of electrons present in all the 's' orbitals, all the 'p' orbitals and all the 'd' orbitals of cesium ion are respectively
Which has maximum paramagnetic character?
The bond angle in AsH3 is greater than that in
The free energy change for the following reactions are given below.
C2H2(g) + (5/2)O2(g) → 2CO2(g) + H2O(l); ∆G° = -1234 kJ C(s) + O2(g)
CO2(g); ∆G° = - 394 kJ H2(g) + (1/2)O2(g) → H2O(l); ∆G° = - 237 kJ
What is the standard free energy change for the reaction H2(g) + 2C(s) → C2H2(g)?
When oxyhaemoglobin changes to deoxyhaemoglobin, Fe 2+ ion changes from
In which part of atmosphere, ozone layer is present?
Xenon hexafluoride reacts with silica to form a xenon compound X. The oxidation state of xenon in X is
What is the number of free electrons present on each carbon atom in graphite?
Which one of the following is used for reviving the exhausted 'permutit'?
Which of the following is not a member of 3d-transition series?
Acetylene and HCHO react in presence of copper acetylide catalyst to form
What is the lowest energy of the spectral line emitted by the hydrogen atom in the Lyman series? (h = Planck's constant, c = velocity of light, R = Rydberg's constant).
Orbital interaction between theσ-bonds of a substituent group and a neighbourinπg orbital is known as
The cell reaction of the galvanic cell Cu(s) | Cu 2+(aq) | | Hg 2+(aq) | Hg(l) is
The noble gas used in atomic reactor, is
Electron affinity values (in kJ mol -1 ) of three halogens X, Y and Z are respectively –349, –333 and –325. Then, X, Y and Z respectively, are
100 mL of 0.015 M HCl solution is mixed with 100 mL of 0.005 M HCl. What is the pH of the resultant solution?
Acidified KMnO4 oxidises oxalic acid to CO2. What is the volume (in litres) of 10 -4 M KMnO4 required to completely oxidise 0.5 L of 10 -2 M oxalic acid in acid medium?
If the standard electrode potential of Cu 2+/Cu electrode is 0.34 V, what is the electrode potential at 0.01 M concentration of Cu 2+ ? (T = 298 K)
One of the elements present in carnalite shows flame colouration. The colour of the flame is
Which of the following is a heterocyclic amino acid?
Which of the following has got incompletely filled f subshell?
The half life of two samples are 0.1 and 0.8 s. Their respective concentration are 400 and 50 respectively. The order of the reaction is
Which one of the following is a lyophilic colloidal solution?
The best method to separate the mixture of ortho-and-para nitrophenol (1 : 1) is :
Which of the following is not correct?
The atomicity of phosphorus is X and the PPP bond angle in the molecule is Y. What are X and Y?
1, 2-dibromoethane reacts with alcoholic KOH to yield a product X. The hybridisation state of the carbons present in X respectively, are
Which one of the following compounds is prepared in the laboratory from benzene by a substitution reaction?
Ethylene glycol reacts with excess of PCl5 to give
Which of the following is a favourable factor for cation formation?
Which one of the following is an exothermic reaction?
Which of the following gives paracetamol on acetylation?
If the boiling point of ethanol (molecular weight = 46) is 78°C, what is the boiling point of diethyl ether? (molecular weight = 74)
If 5% of a radioactive substance dissociates in 15 min, then the time taken by substance to dissociate 99% will be
Which of the following dissolves in water but does not give any oxyacid solution?
Sodium metal crystallises at room temperature in a body centred cubic lattice with a cell edge a = 4.29 Ǻ. The radius of sodium atom is
N2(g) + 3H2(g) 2NH3(g) + 22kcal. The activation energy for the forward reaction is 50 kcal. What is the activation energy for the backward reaction?
At 600°C, Kp for the following reaction is 1 atm. X(g) Y(g) + Z(g) At equilibrium, 50% of X(g) is dissociated. The total pressure of the equilibrium system is p atm. What is the partial pressure (in atm) of X(g) at equilibrium?
Which of the following is not correct regarding the electrolytic preparation of H2O2?
Which of the following is currently used as a true cord?
The solubility of AgCl in 0.2 M NaCl is (Ksp of AgCl = 1.8 x 10 -10 )
In the reactions
A and B are geometrical isomers. Then,
A mixture of amylose and amylopectin is called
Nitrobenzene is reduced by Zn and alcoholic potash mixture to get
Ethyl orthoformate is formed by heating ........................ with sodium ethoxide.
The product formed in the aldol condensation of acetaldehyde is
t-butyl chloride preferably undergo hydrolysis by
Lanthanide contraction is due to increase in
The bisector of the acute angle formed between the lines 4x - 3y + 7 = 0 and 3x - 4y + 14 = 0 has the equation