universe & solar system section 7 MCQ Questions & Answers Detailed Explanation

Answer: (b)

The black color on the sun is because the planet behaved as a black hole during its transit. A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth (or another planet), becoming visible against (and hence obscuring a small portion of) the solar disk.

During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2012 lasted 6 hours and 40 minutes).

Answer: (d)

• Uranus is a planet.
• Moon is a satellite.
• Halley is a comet.
• Mariner is an artificial satellite.

The Mariner program was conducted by the American space agency NASA in conjunction with Jet Propulsion Laboratory (JPL) that launched a series of robotic interplanetary probes designed to investigate Mars, Venus and Mercury from 1962 to 1973.

The program included a number of firsts, including the first planetary flyby, the first pictures from another planet, the first planetary orbiter, and the first gravity assist manoeuvre.

Answer: (d)

The earth is the densest of all the planets.

The density of,

1. Earth is 5.52,
2. Venus–5.50,
3. Mercury 5.27,
4. Mars – 3.95,
5. Jupiter and Saturn – 0.69,
6. Uranus – 11.70.

Answer: (d)

A region of the globe found over the oceans near the equator in the intertropical convergence zone and having weather characterized variously by calm air, light winds, or squalls and thunderstorms is called Doldrums.

Answer: (a)

Composite cone volcanoes, which are also called ‘stratovolcanoes’ or simply ‘composite volcanoes,’ are cone-shaped volcanoes composed of layers of lava, ash, and rock debris.

These steep-sided volcanoes erupt in an explosive manner. It is also called strata cone because of the cataclysmic eruption.

Answer: (c)

• Pleistocene - Human genus
• Paleocene - Frogs
• Permian - Mammals
• Cambrian – Invertebrates