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?
Which instrument is used to measure pressure of gases ?
Metals are good conductors of electricity because
If a rock is brought from the surface of the moon to the earth, then
A body of mass 5 kg is thrown vertically up with a kinetic energy of 490 J. The height at which the kinetic energy of the body becomes half of the original value is ______.
The rate of transfer of charges through a circuit is called?
what Newton made the hypothesis?
A circuit contains two un-equal resistances in parallel
An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at point B. The distance AB is
The weight of a body in a frame of reference is equal and opposite to the force required to prevent it?
Which are the primary Colours ?
The temperature of a gas contained in a closed vessel of constant volume increases by 1°C when the pressure of the gas is increased by 1%. The initial temperature of the gas is ______.
The resistance of a conductor is 5 ohm at 50°C and 6 ohm at 100°C. Its resistance at 0°C is
Consider the following statements in respect of a jet engine and a rocket:
1. A jet engine uses the surrounding air for its oxygen supply and so is unsuitable for motion in space.
2. A rocket carries its own supply of oxygen in the gas form as a fuel.
Which of the above statement(s) is/are correct?
When a neutron is disintegrated to give a b-particle, ______.
At what temperature will the resistance of a copper wire become three times its value at 0°C? (Temperature coefficient of resistance for copper = 4 x 10-3 per 0C)
According to Ohm’s Law? current I = KV, where K is
A current is said to exist whenever _____.
Which instrument is used to determine the intensity of colours ?
Which of the following is not correctly matched?
Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?
The motion on a curved path, when one component of velocity is constant and the other is variable is called?
A In Young's double slit experiment if monochromatic light used is replaced by white light, then _______.
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
The maximum kinetic energy of emitted electrons in a photo electric effect does not depend upon
In order to derive the law of gravitation, Newton assume that the moon’s orbit is?
Read the following statements carefully Y: The resistivity of a semiconductor decreases with increase of temperature Z : In a conducting solid, rate of collisions between free electrons and ions increases with increases of temperature Select the correct statements (s) from the following