The spectrum of a starβs light is measured and the wavelength of one of the lines as thesodiumβs line is found
to be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the
star is
Two satellites are going around the earth at a height of 250 km and 450 km respectively. If angular speed for both
is same, then centripetal acceleration will be.
Two 8 N forces act on each end of the beam of length 0.60m. Two forces are parallel and acting opposite to
each other, the angle between the force and beam is 60o
, what is the torque of the couple exerted on the
beam:
A rigid uniform bar of length 2.4 m is pivoted horizontally at its mid-point, weights are hung from two points
of the bar as shown in diagram. To maintain horizontal equilibrium, a couple is applied to the bar:
What is the torque and the direction of couple?
The frequency and work function of an incident photon are n andππ. If f0 is the threshold frequency, then necessary condition for the emission of photo electron is:
The electron is a cathode-ray tube are accelerated from cathode to anode by a potential differenceof
2000 V. If this p.d is increased to 8000 V, the electrons will arrive at the anode with:
If the radius of the circular path of particle going around the circle is doubled without changing its frequency of
rotation, then centripetal force on it is.
You lift a heavy book from the floor of the room and keep it in the book-shelf having a height 2 m. In this process
you take 5 seconds. The work done by you will depend upon:
