General Science — Part 2 MCQs with Explanations

Modified gunmetal contains lead in addition to the zinc; it is typically composed of 86% copper, 9.5% tin, 2.5% lead, and 2% zinc. It is used for gears and bearings.

On April 20, 1902, Marie and Pierre Curie successfully isolate radioactive radium salts from the mineral pitchblende in their laboratory in Paris. In 1898, the Curies discovered the existence of the elements radium and polonium in their research of pitch blende.

Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula N 2 O.

Actinides are the elements with atomic numbers from 89 to 103.

The two elements that are frequently used for making transistors are Silicon and Germanium.

Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in structure.

In fireworks, the green flame is produced because of barium.

Temporary hardness is due to presence of soluble bicarbonates of calcium and magnesium and permanent hardness is due to the presence of chlorides and sulphate of calcium and magnesium.

Marsh gas, swamp gas, and bog gas is a mixture of methane, hydrogen sulfide, and carbon dioxide, produced naturally within some geographical marshes, swamps, and bogs.

Liquefied Petroleum Gas or LPG consists mainly of methane, propane, propylene, butane, and butylene in various mixtures. It is produced as a by-product of natural gas processing and petroleum refining. The components of LPG are gases at normal temperatures and pressures.

Air is a mixture because we can separate its components while in compound we can not separate it.

Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in refrigerator.

A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air.

Zinc and Gold does not contain a coinage metal.

Major sources of lead emissions to the air today are ore and metals processing and piston-engine aircraft operating on leaded aviation gasoline. The highest air concentrations of lead are usually found near lead smelters.

It has a high dipole moment.

Yttrium is not an isotope of hydrogen.

The main constituents of pearls are Calcium Carbonate and Magnesium Carbonate.

Alloys which contain mercury as one of the contents.

Lithium is the lightest metal of the following.

Mercury remains in liquid form under normal conditions. Mercury remains in the form of liquid in room temperature.

Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.

Here in the given options, Diamond is an element as it is the allotrope of the carbon atom.

Amplitude measures how forceful the wave is. It is measured in decibels or dBA of sound pressure. 0 dBA is the softest level that a person can hear. Normal speaking voices are around 65 dBA.

Reading of a barometer going down is an indication of rainfall.

Decibel is the unit for Intensity of sound.

A fathom is a unit of length in the imperial and the U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water.

Fathom, old English measure of length, now standardized at 6 feet (1.83 metre), which has long been used as a nautical unit of depth.

Light year is a measurement of stellar distances.

Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.

One kilometer is equal to 0.62 mile.

Kilohertz is a unit which measures electromagnetic radio wave frequencies.

Electrical equivalent of one horsepower is 746 watts in the International System of Units (SI), and the heat equivalent is 2,545 BTU (British Thermal Units) per hour.

The bar (symbol bar) is widely used in many countries as a unit of pressure.

One Joule is equal to 10 7 ergs.

The power consumption of small devices is usually measured in Watts, and the power consumption of larger devices is measured in kilowatts (kW), or 1,000 Watts.

An instrument called ammeter measures electric current in a circuit. It is always connected in series in a circuit through which the current is to be measured. Also ammeter has negligible resistance, thus no voltage gets dropped across it.

A chronometer measures time.

A nautical mile measures distance and a knot measures speed.

Knot is a unit of speed of ship.