791. What is the element required for solar energy conversion?
A: Silicon
B: Ultra-pure carbon
C: Beryllium
D: Tantalum
792. Ozone layer protects the Earth from _ radiations from the Sun.
A: Infrared
B: Microwaves
C: X-rays
D: Ultraviolet
793. The nervous system includes which of these major components?
A: Brain & Back Bone
B: Brain
C: Brain, spinal cord, and neurons
D: None
794. An electric current can produce:
A. Chemical effect
B. Heating effect
C. Magnetic effect
D. All of the above*
795. The unit of home electricity energy consumption is:
A. Watt-hour
B. Kilowatt-hour*
C. Joule-hour
D. None of these
796. If the magnet is allowed to move freely, it will always point in the same direction, which is toward the north and south poles, for the following reasons:
A. Gravitational field
B. A lot of metal deposits on north and south poles
C. As a result of the north pole’s attraction and the western pole’s repulsion
D. Earth is a huge magnet*
797. When sound is reflected from the floor, ceiling, or a wall, it mixes with the original sound and changes its complexion; it is called as:
A. Sound
B. Echo
C. Reverberation*
D. Noise
798. The speed of sound in dry air at 20 degrees Celsius is about:
A. 130 meters per second
B. 230 meters per second
C. 330 meters per second*
D. 430 meters per second
799. The speed of light in a vacuum:
A. 300 Million meters per second*
B. 300 million meters per hour
C. 300 million Kilometers per second
D. 300 Million kilometers per hour
800. The time, light takes from the sun to reach the earth is:
A. 8 Minutes*
B. 25 Minutes
C. 45 Minutes
D. 48 Minutes
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