A mass tied to a string is whirled in a horizontal circular path with a constant angular velocity and its angular momentum is L. If the string is now halved, keeping angular velocity same, then the angular momentum will be
In LCR series resonance circuit, choose the wrong statement
Two point charges q1 and q2 are ‘l’ distance apart. If one of the charges is doubled and distance between them is halved, the magnitude of force becomes n times, where n is
A wall is hit elastically and normally by ‘n’ balls per second. All the balls have the same mass ‘m’ and are moving with the same velocity ‘u’. the force exerted by the balls on the wall is
A magnetizing field of 1000 A/m produces a magnetic flux of 2.4 x 10-5 Wb in an iron bar of cross-sectional area 0.3 cm2.The magnetic permeability of the iron bar in SI unit is
For a particular sound wave propagating in air, a path difference between two points is 0.54 m which is equivalent to phase difference of (1.8 π)c. If the velocity of sound wave in air is 330 m/s, the frequency of this wave is
To a bird in air, a fish in water appears to be at 30 cm from the surface. If refractive index of water with respect to air is \(\frac {4}{3}\) ,the real distance of bird from the surface is
If ‘N’ is the number of turns in a circular coil, the value of its self-inductance varies as
Four identical condensers are connected in parallel and then in series equivalent capacitance in series to that in parallel combination is
Two spheres ‘S1’ and ‘S2’ have same radii but temperatures are ‘T1’ and ‘T2’ respectively. Their emissive power is same and emissivity is in the ratio 1 : 4. Then the ratio ‘T1’ to‘T2’ is
A transistor is used as a common emitter amplifier with a load resistance 2 kΩ. The input resistance is 150 Ω. Base current is changed by 20 μA which results in a change in collector current by 1.5 mA. The voltage gain of the amplifier is
A 4 kg mass and a 1 kg mass are moving with equal energies. The ratio of the magnitude of their linear momenta is
A metal disc of radius ‘R’ rotates with an angular velocity ‘ω’ about an axis perpendicular to its plane passing through its centre in a magnetic field of induction ‘B’ acting perpendicular to the plane of the disc. The induced e.m.f. between the rim and axis of the disc is (magnitude only)
Which from following equations is correct for relation between standard cell potential and equilibrium constant?
Which among the following species can act as an acid as well as base according to Bronsted-Lowry theory?
Identify the correct increasing order of energies of molecular orbitals for F2 molecule.
Which among the following nitrogen bases of polynucleotides is NOT derived from pyrimidine?
Which among the following statements is against to the principles of green chemistry?
Under isothermal conditions a gas expands from 0.2 dm3 to 0.8 dm3 against a constant pressure of 2 bar at 300 K. Find the work done by the gas.(1 dm3 bar = 100 J)
Time required for completion of 90% of a first order reaction is ‘t’. What is the time required for completion of 99.9%of the reaction?
lim(x→0)\((\frac {1+tanx}{1+sinx})^{cosec x}\) = ?
20 meters of wire is available to fence of a flowerbed in the form of a circular sector. If the flowerbed is to have maximum surface area, then the radius of the circle is
If the slope of one of the lines given by ax2 + 2hxy + by2 = 0 is two times the other, then
Give that f(x) =\(\frac {1-cos4x}{x^2}\) if x < 0 ,f(x) = a if x = 0 , f(x) =\(\frac {\sqrt {x}}{\sqrt {16 + \sqrt {x} }- 4}\) if x > 0, is continuous at x = 0, then a will be
In a triangle ABC, with usual notations ∠A = 60°, then (1 + \(\frac {a}{c}\) + \(\frac {b}{c}\))(1 + \(\frac {c}{b}\) - \(\frac {a}{b}\)) = ?