Kicked or thrown balls, jumping animals, object thrown from a window, a missile shot from a gun, a bomb released from a bomber plane, etc are all example of?
If the acceleration due to gravity of a planet is half the acceleration due to gravity of earth’s surface and radius of planet is half the radius of the earth, the mass of planet in terms of mass of earth is
Consider the following statements and select the correct code.
Assertion (A): The temperature of a metal wire rises when an electric current is passed through it.
Reason (R): Collision of metal atoms with each other releases heat energy.
Rain is falling vertically downwards. To a man running east-wards, the rain will appear to be coming from
92U235 undergoes successive disintegrations with the end product of 82Pb203. The Number of a and b particles emitted are
Which of the following statements is false ?
At the center of earth dt R, value of “g”?
All electrical appliances are connected in parallel to each other between the main line and the neutral wire to get?
Food gets cooked faster in a pressure cooker because
Two identical solid copper spheres of radius R placed in contact with each other. The gravitational attracton between them is proportional to
lf a black body emits 0.5 joules of energy per second when it is at 27°C , then the amount of energy emitted by it when it is at 627°C will be
Consider the following statements :
(1) A light and a heavy body, having equal momenta, have equal kinetic energies.
(2) The total energy of a body in motion is equal to the work it can do in being brought to rest.
(3) A body cannot have momentum when its energy is zero.
Which of these statement(s) is/are correct ?
On a stationary sail boat, air is blown from a fan attached to the boat. The boat
A 20 cm length of a certain solution causes right handed rotation of 38°. A 30 cm length of another solution causes left handed rotation of 24°. The optical rotation caused by 30 cm length of a mixture of the above solutions in the volume ratio 1 : 2 is
Consider the following statements:
1. A flute of smaller length produces waves of lower frequency.
2. Sound travels in rocks in the form of longitudinal elastic waves only.
Which of the statement(s) given above is/are correct?
A horizontal metal wire is carrying an electric current from the north to the south. Using a uniform magnetic field, it is to be prevented from falling under gravity. The direction of this magnetic field should be towards the______.
Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?
Identify the set in which all the three materials are good conductor of electricity
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?
Suitable impurities are added to a semiconductor depending on its use. This is done in order to
When a battery is connected across a circuit, its potential difference across its terminals is drop and is given by?
A count rate meter shows a count of 240 per minute from a given radioactive source. One hour later the meter shows a count rate of 30 per minute. The half-life of the source is _______.
When a body moves with a constant speed in a circle?
Mica is used in electrical appliances such as electric iron because mica is
A hydrogen-inflated polythene balloon is released from the surface of the earth. As the balloon rises to an altitude up in the atmosphere, it will
Stars which appear single to the naked eye but are double when seen through a telescope are
If we go away from the surface of the earth a distance equal to the radius of earth the value of “g” becomes?
Which of following in not a property of cathode ray.
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 ______.