1. Decibel is the unit of –
A) speed of light
B) intensity of sound
C) intensity of heat
D) None of these
2. Two bulbs are fitted in a room in the domestic electric installation. One of them glows brighter than the other. Then –
A) the brighter bulb has smaller resistance
B) the brighter bulb has larger resistance
C) both the bulbs have the same resistance
D) none of these
3. A car parked in the sun with its windows closed gets terribly hot inside. This is due to –
A) the heat emitted by the engine
B) the greenhouse effect
C) the good conducting power of the metal body
D) the double layered wind shield
4. Which instrument is used to measure sound under water ?
A) Hygrometer
B) Hygroscope
C) Hypsometer
D) Hydrophone
5. Which instrument is used to measure pressure of gases ?
A) Manometer
B) Machmeter
C) Magnetometer
D) Micrometer
6. The working principle of a washing machine is –
A) Centrifugation
B) Dialysis
C) Reverse Osmosis
D) Diffusion
7. “Soap helps in the cleaning of cloths because ” –
A) It reduces surface tension
B) It increases surface tension
C) It absorbs the dirt
D) Of some other reason
8. “Which waves are used in sonography? “
A) Microwaves
B) Sound waves
C) Infrared waves
D) Ultrasonic waves
9. In summer, the mirages are seen due to the phenomenon of –
A) reflection of light
B) total internal reflection
C) interference of light
D) diffraction of light
10. In which part of the eye lies the pigment, that decides the colour of the eyes of a person?
A) cornea
B) choroid
C) lris
D) vitreous body
