1. Which one of the following waves are used by the common TV remote control?
A. Radio waves
B. Lasers
C. Infrared waves
D. Ultrasonic waves
Answer - Option C
2. Given bellow are the psychological manifestations of noise pollution.
(i) Constriction of blood vessels
(ii) Increase in the rate of heart beat
(iii) Digestive spasms
(iv) Dilation of pupil of the eye
Select the correct options
A. (i) and (ii) are correct
B. (i) and (iiI) are correct
C. (ii) and (iv) are correct
D. (i), (ii), (iii) and (iv) are correct
Answer - Option D
3. Which gas is safe and an effective extinguisher for all confined fires?
A. Nitrogen dioxide
B. Carbon dioxide
C. Sulphur dioxide
D. Nitrous Oxide
Answer - Option B
4. Which one of the following statements is incorrect about laser?
A. It is a technique for producing intense beams of light, ultraviolet or infrared radiation of different wavelength.
B. Even in diamond laser beam can drill a hole.
C. A variety of lasers have been made from solids like the ruby crystal and semi conducting materials, liquids and gases.
D. All waves in laser, travel in phase.
Answer - Option A
5. Which one of the following elements the drum of a Photostat machine is made up of:
A. Aluminium
B. Selenium
C. Barium
D. Caesium
Answer - Option B