61. What do we call the temperature and pressure at which solid, liquid, and vapor phases of a particular substance coexist in equilibrium?
A. Equilibrium point
B. Triple point
C. Normal point
D. Elevation point
62. The temperature of boiling water in a steam engine may be high because:
A. there are dissolved substances in water
B. there is low pressure inside the boiler
C. there is high pressure inside the boiler
D. the fire is at a very high temperature
63. An alpha particle is the nucleus of an atom of:
A. Lithium
B. Hydrogen
C. Helium
D. Oxygen
64. Which of the following radiations are used to treat muscle aches?
A. Microwaves
B. Infrared Rays
C. Ultraviolet Rays
D. X-Rays
65. Dielectrics are
A. Non-conducting substances
B. Semi-conducting substances
C. None of the option
D. Conducting substances