Test : General Science - 1 - Defence MCQ

Saw dust is used to cover ice because it is poor conductor of heat. It did not let the ice melt quickly, as it does not transfer the heat of the surrounding to the ice.

The washing machine works on the principle of Centrifugation.

Air is optically rarer than water, the ray of light bends away from the normal at the point of incidence when moving from water to air while it bends towards the normal while moving from air to water. It is clearly visible that the air bubble acts as a DIVERGING LENS (concave lens) in water.

DC implies no changes in value. Frequencies of signals are defined by how many changes per time, e.g. 60 cycles per second. In case of DC with there are 0 changes per second. Hence the frequency of DC is zero.

When a body is moving in a circular path, its average velocity when it complete one cycle in one second is zero.

Carnotite an important uranium ore.

The Montreal Protocol is an international environmental agreement with universal ratification to protect the earth’s ozone layer by eliminating use of ozone depleting substances (ODS) like CFC, which would otherwise allow increased UV radiation to reach the earth.

Malachite is an ore/mineral of copper.

Negative ion which is created by an electron gain and it has more electrons than protons.

Metals conduct electricity because of free electrons.

By volume, Nitrogen is the largest component of the lower atmosphere.

Acetic acid is also known as vinegar.

The reaction of Copper Sulphate and Iron produces Iron Sulphate and Copper. It is a single displacement reaction.

mass of object,m = 60 kg

g = 9.8 m/s^2

So, weight of object on earth = mg

= 60×9.8

= 588 N

Weight of object on moon = 1/6 ×

(weight of object on earth)

= 1/6 × 588

= 98 N

The convex mirror produces an upright image of any object and offers a wide viewing area as compared to the plane mirror. The usage of this type of mirror can be perceived on the car rear-view mirror, side-view mirror and even the motorcycles.

Ultraviolet (UV) radiation from the sun or sunbeds is the main cause of skin cancer.

Metformin is an oral antidiabetic drug for the treatment of diabetes.

- Poliomyelitis is an acute communicable disease of humans caused by a human enterovirus of the Picornaviridae family.
- Tetanus is an infection caused by bacteria called Clostridium tetani.
- Leprosy is a disfiguring disease caused by the Mycobacterium leprae bacteria.
- Plague is caused by the bacteria Yersinia pestis.

Diastole is that part of the cardiac cycle during which the heart refills with blood after the emptying done during systole which is also known as contraction.

Azadirachta indica is botanical name of neem. It is a multipurpose tree that is highly popular in India, where it provides food and insecticide, and is used for its great number of ethnomedicinal properties