Physics - Questions (Section-1)
25Lux is the SI unit of
A. intensity of illuminationB. luminous efficiency
C. luminous flux D. luminous intensity
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26Materials for rain-proof coats and tents owe their water-proof properties to
A. surface tensionB. viscosity
C. specific gravity D. elasticity
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27On a rainy day, small oil films on water show brilliant colours. This is due to
A. dispersionB. interference
C. diffraction D. polarization
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28Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
A. move towards AB. move towards B
C. move at right angles to the line joining A and B D. remain at rest
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29RADAR is used for
A. locating submerged submarinesB. receiving a signals in a radio receiver
C. locating geostationary satellites D. detecting and locating the position of objects such as aeroplanes
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30Sound of frequency below 20 Hz is called
A. audio soundsB. infrasonic
C. ultrasonic D. supersonics
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