It takes much longer to cook food in the hills than in the plains, because
Pa(Pascal) is the unit for
Metals are good conductors of electricity because
A prism having refractive index 1.414 and refracting angle 30° has one of the refracting surfaces silvered. A beam of light incident on the other refracting surface will retrace its path, if the angle of incidence is ______.
The charge on an electron is known to be 1.6 x 10-19 coulomb. In a circuit the current flowing is 1 A. How many electrons will be flowing through the circuit in a second?
Which are the primary Colours ?
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
During a thunderstorm, the thunder in the sky is produced by the
1. meeting of cumulonimbus clouds in the sky
2. lightning that separates the nimbus clouds
3. violent upward movement of air and water particles
Select the correct answer using the codes given below.
The atmosphere exerts enormous pressure on us.But, we don’t feel it because
The period of a satellite in a circular orbit of radius R is T. The period of another satellite in circular orbit of radius 4R is
A satellite is revolving around the sun in a circular orbit with uniform velocity v. If the gravitational force suddenly disappears, the velocity of the satellite will be
Gravitational force is responsible for?
Two resistance r1 and r2 (r1 < r2 ) are connected in parallel. Their equivalent resistance R is
Consider the following statements :
(1) For a spherically symmetric earth, the acceleration due to gravity should be about the same at the equator and at the poles.
(2) If earth suddenly stops rotating about its axis, then the value of g will be same at all the places.
Which of these statement(s) is/are correct ?
The number of dry cells, each of emf 1.5 volt and internal resistance 0.5 ohm that must be joined in series with a resistance of 20 ohm so as to send a current of 0.6 ampere through the circuit is
What is the reason to pivot the compass needle on a sharp pin?
Artificial gravity is produced in a space-craft to?
The internal resistance of a cell of emf 12 V is 5 x 10 -2 Ω . It is connected across an unknown resistance. Voltage across the cell, when a current of 60 A is drawn from it, is
Oil raise up the wick in a lamp. The principle involves
If the change in the value of g at the height h above the surface of the earth is the same as at a depth x below it, then (both x and h being much smaller than the radius of the earth)
Supersonic plane fly with the speed
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?
An artificial gravity can be created in the spacecraft ?
Radiocarbon dating technique is used to estimate the age of
A battery of e.m.f. E has an internal resistance 'r'. A variable resistance R is connected to the terminals of the battery. A current I is drawn from the battery. V is the terminal P.D. lf R alone is gradually reduced to zero, which of the following best describes I and V?
If an electric circuit could be compared to a water circuit at a water park, then the current would be analogous to the ____.
Which instrument is used to measure altitudes in aircraft's ?
Above the surface of the earth if we go to distance equal to double the radius of the earth, the value of ‘g’ will become?
A fan produces a feeling of comfort during hot weather because