The velocity of heat radiation in a vacuum is (1) Equal to that of light (2) Less than that of light (3) Greater than that of light (4) Equal to that of sound Answer: (1) Electrons are generally responsible for heat conduction. The phonons (vibrations of the nuclei) also play a part, depending on the temperature … Read more
On which of the following techniques photo state machine works? (1) Magnetic Image-Making (2) Thermal Image-Making (3) Electrostatic Image-Making (4) Electromagnetic Image-Making Answer: (3) All Electrostatic Copiers work under the premise that a charge of electricity is placed on an Image Drum which has the ability to retain the electric charge much like a capacitor holds … Read more
An ice block with a piece of lead embedded in it floats in water. If the ice melts the water level (1) Rises (2) Falls (3) Remains same (4) Falls first and then rises Answer: (2) If ρ1 is the density of the lead piece of volume v, the volume of water displaced by the ice … Read more
Raindrops fall from a great height. Which among the following statements is true regarding it? (1) they fall with that ultimate velocity, which is different for different droplets (2) they fall with the same ultimate velocity (3) their velocity increases and they fall with different velocity on the earth (4) their velocity increases and they fall … Read more
The velocity of sound in moist air is more than in dry air because the moist air has (1) less dense than dry air. (2) less pressure than dry air. (3) more pressure than dry air. (4) more density than dry air. Answer: (1) The density of dry air is more than that of moist air … Read more
If the diameter of a capillary is doubled, then the rise of water in it will be (1) two times (2) half (3) four times (4) no change Answer: (2) Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if the radius of the tube is doubled, the rise … Read more
Holography is a technique of (1) recording a permanent, sharp two-dimensional black and white or multicolour photograph (2) recording a permanent three-dimensional multicolour photograph (3) recording a permanent three-dimensional black and white photograph (4) recording a permanent three-dimensional photograph of a given single colour or a multicolour Answer: (4) Holography is a technique that enables three-dimensional … Read more
Why the needle of iron swims on the water surface when it is kept gently? (1) It will remain under the water when it will displace more water than its weight (2) the density of the needle is less than that of the water (3) due to surface tension (4) due to its shape Answer: (3) … Read more
A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is (1) the same in both cases in all respects (2) of higher intensity when the train arrives (3) of the higher pitch when the train arrives (4) of the higher pitch when the train departs … Read more
The mass of a star is two times the mass of the Sun. How it will come to an end? (1) Neutron Star (2) Blackhole (3) White Dwarf (4) Red Giant Answer: (1) The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is … Read more