Questions
The energy gained by an object due to change in its shape is
- potential energy
- kinetic energy
- magnetic energy
- electric energy
The quality of a tone
- decreases with loudness
- varies directly as pitch
- depends upon the overtones that are present there
- varies inversely as its frequency
Radar is a/an
- device used for detecting distant objects
- instrument used for measuring rate of chemical reaction
- instrument used for measuring radioactivity
- None of these
The maximum displacement of a vibrating body from its rest or mean position is called its
- time period
- vibration
- frequency
- amplitude
Human beings cannot hear sounds of frequencies below
- 10 Hz
- 15 Hz
- 20 Hz
- 30 Hz
The sky appears blue because the Earth`s atmosphere
- scatters blue light the most
- transmits blue light
- refracts blue light
- refracts blue light more than the light of other colours
A red cross on a white background, when seen through a red filter,
- will appear as red cross on a white background
- will appear as red cross on a black background
- will appear as black cross on a red background
- will become invisible
The working of a dynamo is based on the principle of
- electromagnetic induction
- magnetic effect of current
- heating effect of current
- chemical effect of current
Asha lifts a doll from the floor and places it on a table. If the weight of the doll is known, what else does one need to know in order to calculate the work done by Asha on the doll?
- Time taken
- Height of the table
- Mass of the ball
- Cost of the doll and table
When a body is negatively charged by friction, it means the body has
- lost some electrons
- lost some protons
- acquired excess of electrons
- acquired excess of protons
The condition for an electric charge to flow from one point to another is that the two points must have electric
- circuit
- cell
- current
- potential difference
The line passing through the pole and the centre of curvature of a spherical mirror is called its
- radius of curvature
- principal axis
- focal length
- aperture
If the resistance of a conductor is increased, current will
- increase
- decrease
- remain the same
- first increase and then decrease
Which of the following units is different from the others?
- Joule
- Kilowatt hour
- Erg
- Watt
Which of the following instruments measure(s) time with maximum accuracy?
- Sun dial
- Sand clock
- Quartz clock
- All of the above
Light year is a unit of
- intensity of illumination
- distance
- time
- parallax
Which of the following types of energy cannot be used on a cloudy day?
- Nuclear energy
- Wind energy
- Solar energy
- Geothermal energy
Which process makes it possible to transfer heat in vacuum?
- Radiation
- Convection
- Induction
- Conduction
Which of the following statements is true for a wind energy farm?
- A wind energy farm requires a small area of land.
- The place where the farm is set up should have wind speed of at least 15 km/hr for a major part of the year.
- A wind energy farm is maintenance-free.
- No backup facilities are needed in a wind energy farm.