1 Crore+ students have signed up on EduRev. Have you? Download the App 
The phase difference between the alternating current and e.m.f. is π/2. Which of the following can not be the constituent of the circuit?
The frequency for which a 5 μF capacitor has a reactance of 1/1000 ohm is given by
A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/sec. A plump bob is suspended from the roof of the car by a light rigid rod of length 1.00 m. The angle made by the rod with track is
The approximated wavelength of a photon of energy 2.48eV is
A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to :
The electric field at the centroid of an equilateral triangle carrying an equal charge q at each of the vertices is
A lift of mass 1000 kg is moving with an acceleration of 1 m−s⁻^{2} in upward direction. Tension developed in the string, which is connected to the lift, is
A machine gun fires a bullet of mass 40 g with a velocity 1200 m−s⁻1. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can he fire per second at the most?
A long solenoid has n turns per metre and current I ampere is flowing through it. The magnetic field at the ends of solenoid is
Two pieces of a glass plate, placed one upon the other with a little water in between them, can not be separated easily, because of
The sum of two vectors A → and B → is at right angles to their difference. Then
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A):In a nuclear reactor cadmium acts as a moderator.
Reason(R):The cadium rods are so inserted in the graphite block so that they can be slided in and out as per requirement.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A): Energy density in the solenoid is greater at centre than near its ends.
Reason(R): Energy density is defined as
A solid cylinder of mass M and radius R rolls down an inclined plane without slipping. The speed of its centre of mass when it reaches the bottom is
There are two lead spheres at the same temperature, the ratio of radii being 1:2 The ratio of head capacities are
For the constructive interference the path difference between the two interfering waves must be equal to
The fundamental unit which has the same power in the dimensional formula of surface tension and viscosity is
If a star is moving towards earth, then the lines are shifted towards
A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is
When a tuning fork of frequency 341 is sounded with another tuning fork, six beats per second are heard. When the second tuning fork is loaded with wax and sounded with the first tuning fork, the number of beats is two per second. The natural frequency of the second tuning fork is
Singly ionized helium (He^{+}) atom is hydrogen like in the sense that a solitary electron revolves around a positively charged nucleus. If the energy of this electron in its first orbit (n = 1) is 54.4 eV, what will be its energy in the first excited state?
The charge deposited on 4 μ F capacitor in the circuit is
The angular velocity of the second needle in watch (in rad/s) is
We are able to obtain fairly large currents in a conductor because
A charge +4q is located on the Xaxis of a Cartesian coordinate system at x = 2a as shown. Another charge +(q/4) is located on the Xaxis at x = a. Where on the Yaxis should a third charge 3q be placed so that the resultant electric field at the origin O has equal positive X and Y components?
A charged particle with velocity 2 x 10^{3} m/s passes undeflected through electric and magnetic field. Magnetic field is 1.5 telsa. The electric field intensity would be
The correct order of boiling points for primary (1º), secondary (2º) and tertiary (3º) alcohols is
Which of the following does not undergo Cannizzaro's reaction?
DNA has deoxyribose, base and a third compound, known as
For reaction at equilibrium, Le Chatelier's principle predicts the effects of
For an endothermic reaction, energy of activation is E_{a} and enthalpy of reaction is ΔH (both of these in kJ/mol). Minimum value of E_{a} will be
In the reaction CH_{2}COOH_{aq} + OH_{(aq)} → CH_{3}COO^{} + H_{2}O_{(l)} ; ΔH = 55.2kJ mol^{1} What is the heat of dissociation (in kJ mol^{1}) of acetic acid?
Which of the following complexes will have four isomers?
Compound A has a molecular formula C₇H₇NO on treatment with Br₂/KOH, A gives an amine B which respond to carbylamine test. B on diazotisation and coupling with phenol give an azo dye. A can be
The amount of Aluminium deposited when 0.1 Faraday current is passed through aluminium chloride will be (R = 27)
A solution of AgNO_{3} during electrolysis between silver electrodes required a quantity of 241.25 coulombs of electricity the weight of silver deposited is
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
Identify the indicator used to titrate Na₂CO₃ solution with HCl
A white salt is readily soluble in water and gives a colourless solutions with a pH of about 9.The salt would be
Which of the following compounds will show positive silver mirror test?
Among the following compounds the decreasing order of reactivity towards electrophilic substitution is:
For preparing an alkane ,a concentrated aqueous solution of sodium or potassium salt of a saturated carboxylic acid is subjected to
AB is an ionic solid. If the ratio of ionic radii of A^{+} and B^{ − } is 0 . 52. What is the coordination number of B^{ − }
A 100 g solution contains 25 g of water, 25 g ethanol and 50 g acetic acid. The mole fraction of water is
An activated complex molecule differs from a normal molecule of the same atomicity in that it has__
The electrons, identified by quantum numbers n,l (i) n = 4, l = 1, (ii) n = 4, l = 0, (iii) n = 3, l = 2, (iv) n = 3, l = 1 can be placed in order of increasing energy, from the lowest to highest, as_
Which one of the following platinum complexes is used in cancer chemotherapy?
If 0.6387 of plantinichloride of a monoacid base on ignition gave 0.209g of platinum, then molecular weight of the base is
The area, in square unit, of the region bounded by the curve x^{2} = 4 y , the line x = 2 and the xaxis is
The equation of the circle described on the common chord of the circles x^{2 }+ y^{2} 8x + y 15 = 0 and x^{2} + y^{2}  4x + 4y  42 = 0 as diameter is
If p and q are the roots of the equation x^{2} + px + q = 0, then
The solution of the equation y  x(dy/dx)=a[(y^{2})+(dy/dx)] is
"If Deb and Sam go to the mall, then it is snowing."
Which statement below is logically equivalent?
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
A committee of n persons is to be formed out of 30 persons.
Assertion(A) : The value of n for which the number of committees is maximum is n = 15
Reason(R) : In the expansion of the middle term has the greatest binomial coefficient.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A):The angle between the lines 2x = 3y = z and 6x =  y =  4z , is 90^{0} .
Reason(R): If and and angle between them is θ , then
A and B are square matrices of order n x n, then (A  B)^{2} is equal to
The equation of the normal to the curve x^{2} = 4y at (1, 2) is
If ^{2n}C_{3}:^{n}C_{2}=44:3.For which value of r, ^{n}C_{r}=15?
If a dice is thrown twice, the probability of occurrence of 4 at least once, is
A student obtain 75%, 80% and 85% in three subjects. If the marks of another subject are added, then his average cannot be less than
The equation of the sphere passing thro' the point (1,32) and the circle y^{2}+z^{2}=25 and x=0 is
Given that θ is a acute and that sin θ =3/5. Let x,y be positive real numbers such that 3(xy) =1, then one set of solutions for x and y expressed in terms of θ is given by
The length of subtangent to x^{2} + xy + y^{2} = 7 at 1, − 3 is
A and B are non  zero square matrices of the same order. Which is correct?
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A):
Reason(R): If f(x) is a periodic function of period a, then
If minimum value of f(x) = x^{2} + 2bx + 2c^{2} is greater than maximum value of g(x) =  x^{2 } 2cx + b^{2 }then for x is real
Let f(x) =ax^{2}+bx+c,a≠0 and triangle = b^{2}4ac.If α+β, α^{2}+β^{2} and α^{2}+β^{2} are in G.P., then :
1 videos356 docs217 tests
