Consider the following statements. Work is not done, when:
1. a man is walking on a horizontal road.
2. a man is climbing up a hill.
3. a man with a load on his head is walking on a horizontal road.
4. moon is revolving round the earth.
Which of the statements given above are correct?
The distance from the center of earth to the center of the moon’ is called as?
If the linear momentum of a body is increased by 50%, then the kinetic energy of that body increases by _____
The unit of temperature coefficient of resistivity is?
Conductance is the reciprocal of?
Atom is the smallest part of matter which takes part in chemical reactions.
An observer is moving with half the speed of light towards a stationary microwave source emitting waves at frequency 10 GHz. What is the frequency of the microwave measured by the observer?
(speed of light = 3 × 108 ms–1)
The drift velocity of mobile charge carriers in electric circuits is ____.
The maximum current that can be measured.by a galvenometer of resistance 400 is 10 mA. It is converted into a voltmeter that can read upto 50 V. The resistance to be connected in series with the galvanometer is (in ohm).
A beam of light of wavelength 600 nm from a distant source falls on a single slit 1mm wide and the resulting diffraction pattern is observed on a screen 2m away. The distance between the first dark fringes on either side of the central bright fringe is _______.
It is more difficult to walk on a sandy road than on a concrete road because
ln which of the processes, does the internal energy of the system remain constant?
According to Einstein's photoelectric equation, the graph of K.E. of the photoelectron emitted from the metal versus the frequency of the incident radiation gives a straight line graph, whose slope ______.
out of the following, which is not emitted by radioactive substance?
Astronauts experiences weightlessness when their spacecraft is?
Consider the following statements and select the correct code.
Assertion (A): The velocity of sound in air increased due to the presence of moisture in it. Reason (R): The presence of moisture in air lowers the density of air.
When a neutron is disintegrated to give a b-particle, ______.
Pendulum clocks become slow in summer because
If escape velocity from the earth’s surface is 11.2 km/sec. then escape velocity from a planet of mass same as that of earth but radius one fourth as that of earth is
The projectile motion and circular motion are good example of ?
The total flight requires a time that is?
Radio telescopes are better than optical telescopes because
Consider the following statements:
1. Light of longer wavelength is scattered much more than the light of shorter wavelength.
2. The speed of visible light in water is 0.95 times the speed in vacuum.
3. Radio waves are produced by rapidly oscillating electrical currents.
4. To detect the overspeeding of vehicles, police use the Doppler effect to reflected short radio waves.Which of these statements are correct?
When body is raised to a height equal to radius of earth, the P.E. change is
For one complete revolution θ =?
Consider the following statements:
A body weighs less at the equator than at the poles because:
1. earth rotates about its axis.
2. the ice cap at the poles increases gravitational pull.
3. equatorial diameter is greater than the polar diameter.
4. of some unknown facts.
Which of the statements given above is/are incorrect?
Electromotive force may be defined as the?
A fan produces a feeling of comfort during hot weather because