20054.Isotopes of an element contain
the same number of protons but different number of neutrons
the same number of neutrons but different number of protons
equal number of protons and electrons
equal number of nucleons
20052.ML2T-2 is the dimensional formula for
moment of inertia
pressure
elasticity
couple acting on a body
20015.Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2
0.14 m/s
140 m/s
1.4 km/s
14 m/s
20050.Rainbow is due to
absorption of sunlight in minute water droplets
diffusion of sunlight through water droplets
ionisation of water deposits
refraction and reflection of sunlight by water droplets
20019.Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
move towards A
move towards B
move at right angles to the line joining A and B
remain at rest
20043.Out of the following pairs, which one does not have identical dimension?
Moment of inertia and moment of a force
Work and Torque
Angular momentum and Plancks constant
Impulse and Momentum
20039.Intensity of sound at a point is ____ its distance from the source.
directly proportional to
inversely proportional to
directly proportional to square of
inversely proportional to square of
20056.Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?
Scattering
Diffraction
Interference
Polarization
20038.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?
1.8 km, 0.15 km
2.2 km, 0.20 km
2.8 km, 0.25 km
3.3 km, 0.30 km
20025.Stars twinkle because
the intensity of light emitted by them changes with time
the distance of the stars from the earth changes with time
the refractive index of the different layers of the earths atmosphere changes continuously, consequently the position of the image of a start changes with time
the light from the star is scattered by the dust particles and air molecules in the earths atmosphere
20049.On a stationary sail boat, air is blown from a fan attached to the boat. The boat
moves in opposite direction in which the air is blown
does not move
moves in the same direction in which air blows
spins around
20011.out of the following, which is not emitted by radioactive substance?
Electrons
Electromagnetic radiations
Alpha particles
Neutrons
20047.Supersonic plane fly with the speed
less than the speed of sound
of sound
greater than the speed of sound
of light
20026.It takes much longer to cook food in the hills than in the plains, because
in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil
in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere
in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking
20034.Superconductors are substances which
conduct electricity at low temperature
offer high resistance to the flow of current
offer no resistance to the flow of electricity
conduct electricity at high temperatures
20002.Siphon will fail to work if
the densities of the liquid in the two vessels are equal
the level of the liquid in the two vessels are at the same height
both its limbs are of unequal length
the temperature of the liquids in the two vessels are the same
20051.Stars which appear single to the naked eye but are double when seen through a telescope are
novas and supernovas
binaries
asteroids
quasars