Mix Test - 4

As we move away from the sun in the solar system time taken by planets to complete one orbit around the sun increases.

• Over the course of a year, Earth moves sometimes closer to the sun and sometimes farther away from the sun. 
• Earth's closest approach to the sun, called perihelion, comes in early January and is about 91 million miles (146 million km).
• The farthest from the sun-earth gets is called aphelion.
• Right now, the Earth is slowly drifting away from the Sun, driven by the relentless effect of nuclear fusion on the Sun.
• As time goes on, the Sun burns through more and more of its fuel, losing mass in the process and loosening its gravitational grip on the Earth.

Hence, the correct option is (C).

Pure carbon can be found in three different forms; diamond, graphite, and carbon black. Diamond and graphite are both crystalline but differ in the way their atoms are arranged. Diamond is the hardest naturally occurring substance known, while graphite is soft and slippery. Graphite is also a good conductor of both heat and electricity and is used as a lubricant and as the "lead" of pencils. Both diamond and graphite can be made artificially and are usually inert but, under the right circumstances, can be made combined with oxygen. Diamonds do burn.

Hence, the correct option is (A).

Agriculture waste is organic waste and it does not pollute the water.

The causes of water pollution are Industrial waste, Wastewater and sewage, Marine Dumping, Oil Spills, Mining waste, Industrial waste, Radioactive waste, etc.

Hence, the correct option is (C).

The burning of fossil fuels causes Global warming and the melting of polar ice caps.

The primary cause of global warming is human activity that releases carbon into the atmosphere, most significantly the burning of fossil fuels to drive cars, generate electricity, and operate our homes and businesses.

Hence, the correct option is (D).

Cellulose fibres can be used to create a wide range of fabrics, from heavy denim or corduroy to a light muslin or organza.

Examples of cellulose fibres include Rayon, Linen, Jute, Hemp, Cotton, Ramie, and Sisal.

Common non-cellulosic fibres include Nylon, Olefin, Acrylic, Polyester and Spandex.

Hence, the correct option is (D).

Visible Light: A portion in the spectrum of electromagnetic waves that is visible to the human eye, ranging roughly between 380 to 700 nm.

• Red has the longest wavelength and lowest frequency in this visible spectrum.
• Violet has the smallest wavelength and highest frequency in the visible spectrum.
• They are arranged in wavelength increasing order of VIBGYOR (Violet, Indigo, Blue, Green, Yellow, Orange, and Red).

The human eye can detect electromagnetic radiation in the range of wavelength 380nm to 700 nm.

Hence, the correct option is (B).

The statements A and C are correct.

• The imaginary line which divides the parts of the earth with day and night is called the circle of illumination.
• The circle of illumination is at a right angle to the orbital plane.
• Thus, the circle of illumination is at an angle of 23.5º to the earth’s axis.
• It divided the equator into two equal halves.
• Because of the angle between the circle of illumination and the axis; both the hemispheres of the earth do not get the same amount of light on most of the days.

Hence, the correct option is (C).

Copper is the most conductive metal of electricity.

Conductivity is the measure of the ease at which an electric charge or heat can pass through a material. Electrical conductivity in metals is a result of the movement of electrically charged particles.

Hence, the correct option is (A).

Tsunami is caused due to disturbance caused deep down the sea. Lightening will not cause any disturbance for the sea whereas earthquake, A major nuclear explosion undersea and Volcanic eruption can cause a disturbance in the sea.

Hence, the correct option is (D).

Brittleness is generally found in non-metals.

The property of metals by which they can be beaten into thin sheets is known as malleability, e.g. copper, aluminium.

The property of metals by which they can be drawn into thin wires is known as ductility, e.g. gold, silver.

Metals are malleable and ductile in nature whereas non-metals are neither malleable nor ductile; they are brittle.

Hence, the correct option is (D).