Two speakers connected to the same source of fixed frequency are placed 2.0 m apart in a box. A sensitive microphone placed at a distance of 4.0 m from their midpoint along the perpendicular bisector shows maximum response. The box is slowly rotated until the speakers are in line with the microphone. The distance between the midpoint of the speakers and the microphone remains unchanged. Exactly five maximum responses are observed in the microphone in doing this. The wavelength of the sound wave is:
The minimum energy required to eject an electron, from the metal surface is called
A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is undergoing circular motion is the x − y plane with centre at O and constant angular speed ω. If the angular momentum of the system, calculated about O and P are denoted by , respectively, then
A non-planar loop of conducting wire carrying a current I is placed as shown in the figure. Each of the straight sections of the loop is of length 2a. The magnetic field due to this loop at the point P (a, 0, a) points in the direction
A raindrop falls near the surface of the Earth with almost uniform velocity because
Two diodes have a resistance of 20 ohm and are centre-tapped with rms secondary voltage from centre tap to each end of secondary voltage of 50 V. If the external resistance is 980 ohm, then what is the mean load?
A spring scale is adjusted to read zero. Particles of mass 1 g fall on the pan of the scale and collide elastically and they rebound upward with the same speed. If the height of fall of particles is 2 metres and their rate of collision is 100 particles per second, then the scale reading (in grams) will be
A rocket is fired from Earth to the Moon. The distance between Earth and the Moon is r and the mass of Earth is 81 times the mass of the Moon. The gravitational force on the rocket will be zero when its distance from the Moon is
A stone is projected from a point on the ground in such a way so as to hit a bird at height 3h and could attain a maximum height 4h above the ground. If at the instant of projection, the bird flies away horizontally with speed 10 m s−1 and the stone still hits the bird while descending, then the horizontal velocity of stone is
Which among the following species have square planar geometry around the central atom?
(i) XeF4
(ii) SF4
(iii) [NiCI4]2-
(iv) [PtCI4]2-
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of Cu2O with
How many chain isomers could be obtained from the alkane C6H14?
The reduction potential at pH = 14 for the Cu2+/Cu couples is
[Given, = 0.34 V; Ksp[Cu(OH)2] = 1 x 10-19]
From a well shuffled pack of playing cards, two cards drawn one by one with replacement. The probability that both are aces is
Suppose ω is an imaginary cube root of unity. If (1+ω2)m = (1+ω4)m, then the least positive integral value of m is
If b,c and sinB are given such that ∠B is acute and b<c sinB, then
For all real x, the minimum value of 1 - x + x2/1 + x + x2 is
The mode of the following items is 0,1,6,7,2,3,7,6,6,2,6,0,5,6,0, is
AOB is the positive quadrant of the ellipse x2/a2 + y2/b2 = 1, where OA = a, OB = b. The area between the arc AB and the chord AB of the ellipse is
\'A\' draws two cards with replacement from a pack of 52 cards and \'B\' throws a pair of dice. What is the chance that \'A\' gets both cards of same suit and \'B\' gets total of 6?
If the roots of the equation x2+2mx+m2-2m+6=0 are equal, then the value of m is
The point on the axis of y which is equidistant from (-1, 2) and (3, 4) is
In how many ways can 5 prizes be given to 4 students if any student can receive more than one prize?
The values of 'θ' satisfying sin 7θ = sin 4θ - sin θ in 0 < θ < π/2 are