universe & solar system section 6 Practice Questions Answers Test with Solutions & More Shortcuts

Answer: (b)

From electromagnetic radiation to the revolution of the earth, everything is responsible for bringing dynamic changes on the surface of the earth. For example,

Electromagnetic radiation brings changes in the field of microwaves, wavelengths of radio, UV rays, infrared rays, X rays, and gamma rays.

Geothermal energy is the heat received from the earth’s core. This heat continuously flows outward. It transfers to the surrounding layers of rock, the mantle. When temperature and pressure become very high some mantle rocks melt becoming magma. It then either comes out as lava or heats up the nearby rocks and water which comes out as hot springs or geysers.

Gravitational force is constantly working on all physical bodies. It is giving weights to objects with mass and causes them to fall to the ground when dropped. Plate movement is a dynamic change on the surface of the earth. It explains many aspects of the interrelationship of volcanoes, earthquakes, climate change, and the evolution of life itself.

Everything about our planet is related either directly or indirectly to plate tectonics. Rotation causes day and night. Revolution causes seasons, change in the length of day and night.

Answer: (d)

Kepler’s second law of planetary motion describes the speed of a planet traveling in an elliptical orbit around the sun. It states that a line between the sun and the planet sweeps equal areas in equal times.

Thus, the speed of the planet increases as it nears the sun and decreases as it recedes from the sun.

Answer: (c)

The Earth is the densest of all the planets in our solar system. The density of the Earth is 5.513 g/cm3. This is an average of all of the material on the planet.

Answer: (d)

Only 1st and 2nd are correct.

Answer: (c)