The bulk modulus of a spherical object is 'B'. If it is subjected to uniform to uniform pressure 'p', the fractional decrease in radius is:
A rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angluar acceleration of the cylinder if the rope is pulled with a force of 30 N?
25
If and be the apparent angles of dip observed in two verical planes at right angles to each other, then the true angle of dip is given by:-
A 250-turn rectangular coil of length 2.1cm and width 1.25cm carries a current of 85 and subjected to magnetic field of strength 0.85T. Work done for rotating the coil by against the torque is
4.55
2.3
1.15
9.1
A long solenoid of diameter 0.1m has turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0A from 4A in 0.05s. If the resistance of the coil is . the total charge flowing through the coil during this time is:
16
32
16
32
In an electromagnetic wave in free space the root mean square value of the electric field is . The peak value of the magnetic field is:-
A physical quantity of the dimensions of length that can be formed out of c, G and is (c is velocity of light, G is universal constant of gravitation and e is charge)
Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities _{1} and _{2}. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is:
Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t_{1}. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t_{2}. The time taken by her to walk up on the moving escalator will be:
Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is (e + e). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then e is of the order of [Given mass of hydrogen m_{h} = 1.67 x 10^{-27} kg]
10^{-20} C
10^{-23} C
10^{-37} C
10^{-47} C
Two cars moving in opposite directions approach each other with speed of 22 m/s and 16.5 m/s respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is [velocity of sound 340 m/s]:
350 Hz
361 Hz
411 Hz
448 Hz
One end of string of length 1 is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed v, the net force on the particle (directed towards centre) will be (T represents the tension in the string)
zero
T
Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:
g, g
A gas mixture consists of 2 moles of O_{2} and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is
4 RT
15 RT
9 RT
11 RT
A Carnot engine having an efficiency of as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is :
1 J
90 J
99 J
100 J
The x and y coordinates of the particle at any time are x = 5t - 2t^{2} and y = 10t respectively, where x and y are in meters and t in seconds. The acceleration of the particle at t = 2s is
0
5m /s^{2}
-4m /s^{2}
-8m /s^{2}
Answer is 3rd option
Young's double slit experiment is first performed in air and then in a medium other than air. It is found that 8^{th} bright fringe in the medium lies where 5^{th }dark fringe lies in air. The refractive index of the medium is nearly:
1.25
1.59
1.69
1.78
Two Polaroids P_{1} and P_{2} are placed with their axis perpendicular to each other. Unpolarised light I_{0} is incident on P_{1}. A third polaroid P_{3} is kept in between P_{1} and P_{2} such that its axis makes an angle 45° with that of P_{1} . The intensity of transmitted light through P_{2} is:
A thin prism having refracting angle 10° is made of glass of refractive index 1.42. This prism is combined with another thin prism of glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be :
4°
6°
8°
10°
A person can see clearly objects only when they lie between 50 cm and 400 cm from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be
convex, + 2.25 diopter
concave, - 0.25 diopter
concave, - 0.2 diopter
convex, + 0.15 diopter