Questions and answers for exam Preparation

MCQs

Total Questions : 292 | Page 29 of 30 pages

Question 281. In science, a broad idea that has been repeatedly verified so as to give scientists great confidence that it represents reality is called

a theory
a Ptolemaic model
a paradigm
a hypothesis

Discuss Question

Answer: Option A. -> a theory
:
A

Question 282. Only one of the statements below uses the term theory in its correct scientific sense. Which one?

Evolution is only a theory, so there's no reason to think it really happened.
Einstein's theory of relativity has been tested and verified thousands of times.
I wrote a theory that is 152 pages long.
I have a new theory about the cause of earthquakes, and I plan to start testing it soon.

Discuss Question

Answer: Option B. -> Einstein's theory of relativity has been tested and verified thousands of times.
:
B

Question 283. Which of the following is not consistent with the major hallmarks of science?

Scientific explanations should be based solely on natural causes.
A scientific model must make testable predictions.
Science progresses through the creation and testing of models that explain observation as simply as possible.
Science consists of proven theories that are understood to be true explanations of reality.

Discuss Question

Answer: Option D. -> Science consists of proven theories that are understood to be true explanations of reality.
:
D

Question 284. Earth is farthest from the Sun in July and closest to the Sun in January. During which Northern Hemisphere season is Earth moving fastest in its orbit?

winter
spring
summer
fall

Discuss Question

Answer: Option A. -> winter
:
A

Question 285. When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?

Copernicus used perfect circles for the orbits of the planets.
Copernicus placed the Sun at the center, but did not realize that the Moon orbits Earth.
Copernicus misjudged the distances between the planets.
Copernicus placed the planets in the wrong order going outward from the Sun.

Discuss Question

Answer: Option A. -> Copernicus used perfect circles for the orbits of the planets.
:
A

Question 286. Galileo challenged the idea that objects in the heavens were perfect by

inventing the telescope
showing that heavy objects fall at the same rate as lighter objects
proving Kepler's laws were correct
observing sunspots on the Sun and mountains on the Moon

Discuss Question

Answer: Option D. -> observing sunspots on the Sun and mountains on the Moon
:
D

Question 287. Consider the following statements :
1. Ocean currents are the slow-surface movement of water in the ocean.
2. Ocean currents assist in maintaining the Earth's heat balance.
3. Ocean currents are set in motion primarily by prevailing winds.
4. Ocean currents are affected by the configuration of the ocean.
Which of these statements are correct?

1 and 2
2, 3 and 4
1, 3 and 4
1, 2, 3 and 4

Discuss Question

Answer: Option B. -> 2, 3 and 4
:
B
Ans. (b)
Explanation
The ocean currents are not only slow but also could be fast. So, statements 2, 3 and 4 are correct.

Question 288. Assertion (A): Existence of human life on Venus is highly improbable.
Reason (R): Venus has extremely high level of carbon dioxide in its atmosphere.

Both A and R are true and R is the correct explanation of A
Both A and R are true but R is NOT the correct explanation of A
A is true but R is false
A Js false but R is true

Discuss Question

Answer: Option A. -> Both A and R are true and R is the correct explanation of A
:
A
Ans. (a)
Explanation
Venus second closest planet after Mercury to the Sun is often considered 'Earth's twin' because of their close proximity in size, mass (weight) and density. Existence of human life is highly improbable because of high levels C0₂ in its atmosphere.

Question 289. Assertion (A): The amount of moisture in the atmosphere is related to latitude.
Reason (R): The capacity to hold moisture in the form of water vapour is related to temperature.

Both A and R are true and R is the correct explanation of A
Both A and R are true but R is NOT the correct explanation of A
A is true but R is false
A Js false but R is true

Discuss Question

Answer: Option A. -> Both A and R are true and R is the correct explanation of A
:
A
Ans. (a)
Explanation
The amount of moisture in the atmosphere is related to latitude. Because, according to the change in latitudes, temperature also varies on the earth. Temperature directly influences the moisture holding capacity of the atmosphere.

Question 290. Assertion (A): The same face of the Moon is always presented to the Earth.
Reason: The Moon rotates about its own axis in 23V-i days which is about the same time that it takes to orbit the Earth.

Both A and R are true and R is the correct explanation of A
Both A and R are true but R is NOT the correct explanation of A
A is true but R is false
A Js false but R is true

Discuss Question

Answer: Option C. -> A is true but R is false
:
C
Ans. (c)
Explanation
Moon rotates more slowly than the Earth and takes little over 27 days to rotate once. Since it takes about the same time to revolve around the earth, it always presents the same face or hemisphere to the Earth. Hence R is not correct statement.