The source of the Sun’s energy is the process of ____________?

A. Photoelectric emission
B. Nuclear fission
C. Nuclear fusion
D. Thermionic emission

The audio signals of TV are _____________?

A. Amplitude modulated
B. Frequency modulated
C. Fixe modulated
D. Velocity modulated

The owl can see most clearly in total darkness because:

A. It has squint eyes
B. It has light bulbs in its eyes provided by nature
C. It produces infrasonic sounds
D. It has large eyes with orbs directed forward, giving it binocular sight

A photostat machine works on _____________?

A. Electromagnetic image making
B. Magnetic image making
C. Thermal image making
D. Electrostatic image making

To measure the speed of an approaching car a police officer shines?

A. Light waves on it
B. Microwaves on it
C. Radio waves on it
D. Ultra high frequency waves on it

Rainbow is seen after rain because of hanging molecules of water which act as __________?

A. Lens
B. Prism
C. Mirror
D. Slabs

Main use of salt in diet is to : ___________?

A. Ease the process of cooking
B. Increase the taste
C. Produce small amount of hydrochloric acid required for digestion
D. Inclease solubility of food particles in water

Black foot disease is caused by the pollution of groundwater as a consequence of increased seepage of:__________?

A. Nitrates
B. Fluorides
C. Arsenic
D. Mercury

pH value of water is _________?

A. 5
B. 5-6
C. 8.7-10.5
D. 6.5-8.5

pH value of Blood or Red Blood Cells ?

A. 5
B. 6
C. 7.35-7.45
D. 8-10