The best conductor of heat among the following is –
(a) Alcohol
(b) Mercury
(c) Ether
(d) Water
Answer: (b) Mercury
Explanation: Conductance of mercury = 8.395 W/m-K, Methyl Alcohol = 0.202 W/m-K, Ether = 0.130 W/m-K, Water = 0.609 W/m-K
(a) Increases
(b) Decreases
(c) Remains unaltered
(d) Drops suddenly
Answer: (c) Remains Unaltered
Explanation: Speed of light remains constant, always.
The blue moon phenomenon occurs-
(a) When two full moons occur in the same month
(b) When four full moons appear in two consecutive months of same calendar year
(c) When two full moons appear in the same month thrice in a calendar year
(d) None of the above
Answer: (a) When two full moons occur in the same month
Consider the following statements –
1. The Earth receives the Sun’s energy at the infrared end of the spectrum
2. The Earth re-radiates the Sun’s heat as ultraviolet energy
Which of the statements given above are/is correct –
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (d) Neither 1 nor 2
Largest planet in our solar system is –
(a) Mars
(b) Jupiter
(c) Saturn
(d) Neptune
Answer: (b) Jupiter
Explanation: Planets in largest to smallest series - Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury
Meteorites are the heavenly bodies –
(a) Between the Mars and the Jupiter
(b) Between the Saturn and the Neptune
(c) Between the Mars and the Venus
(d) That burn brightly on entering the Earth atmosphere
Answer: (d) That burn brightly on entering the Earth atmosphere
Light-year measures which of the following –
(a) Intensity of light
(b) Mass
(c) Distance
(d) Time
Answer: (c) Distance
Explanation: One Light Year is equals to the distance traveled by light in one year.
Which of the following statements about the use of radioactive isotopes is correct?
(a) In medicine, they are used as tracers for diagnostic purposes
(b) In industry, they are used to detect leak in water, oil and gas pipelines
(c) They are used to determine the age of rocks and fossils
(d) All of these statements are correct
Answer: (d) All of these statements are correct
Clear nights are colder than cloudy nights because of –
(a) Conduction
(b) Condensation
(c) Radiation
(d) Insolation
Answer: (c) Radiation
Explanation: radiation from earth surface gets trapped near surface only because of clouds and thus keeps nights warmer.
German silver is an alloy of
(a) Copper, silver and zinc
(b) Copper, nickel and zinc
(c) Silver, tin and zinc
(d) Silver, nickel and zinc
Answer: (b) Copper, nickel and zinc
At upper atmosphere, an astronaut feels –
(a) Extremely hot
(b) Slightly hotter
(c) Extremely cold
(d) Slightly cooler
Answer: (c) Extremely cold
Explanation: The warmth felt near earth surface and in atmosphere is because of radiation of heat by earth surface, which can be found in lower atmosphere.