Following is not a property of radiation
It travels with velocity of light
Medium is necessary for propagation
Its nature is electromagnetic
It has quantum nature
Which of the following characteristics of sound depend on the amplitude of vibrations?
Speed
Pitch
Loudness
Quality
The amount of matter in same weight will be
least at North pole
least at equator
least at Moon
same at all of the above places
Select the group of poor conductors of heat from the following.'
Air, water, plastic
Wool, wood, iron
Water, copper, wood
Air, aluminium, wool
Select the one which is different from the others in the manner it is applied.
Electrostatic force
Frictional force
Gravitational force
Magnetic force
While teaching the topic on 'Motion and Time' to Class VII students, Savita gave examples of different kinds of motion to the students. Which one of the following examples was quoted by her incorrectly?
Motion of a boy sitting in a moving car in relation to the car
Motion of a boy sitting in a merry-go-round
Motion of the hammer of an electric bell
Motion of a cricket ball hit by a batsman
Which one of the following is not an example of electromagnetic waves?
Ultraviolet rays
Radio waves
X-rays
Sound waves in air
Radiation with maximum penetration power is
infrared radiation
ultraviolet radiation
X-rays
-rays
The mass of man is 72 kg at Earth. The value of g at the Moon's surface is 1/6 of that on the Earth. The mass of man at the Moon will be
12 kg
120 kg
72 kg
432 kg