21. Consider the following statements regarding a body in uniform circular motion:
- There is no change in speed.
- There is no change in amplitude.
- There is no change in velocity.
- There is no change in acceleration.
Which of the above statements is / are correct?
[A] Only 1
[B] 1 and 2
[C] Only 2
[D] 1, 2 and 3
Show Answer
Correct Answer: C [Only 2]
Notes:
In uniform circular motion, the speed and amplitude (the radius or distance from the center) remain constant. However, the velocity, which includes direction, continually changes due to the change in direction of motion. The acceleration is also non-zero (centripetal acceleration). Therefore, only statements 1 and 2 are correct.
22. Consider the following statements regarding the motion of an elephant and a feather when dropped from the same height:
- The elephant encounters a smaller force of air resistance than the feather and therefore falls faster.
- The elephant has a greater acceleration due to gravity than the feather and therefore falls faster.
- Both elephant and feather have the same force of gravity, yet the acceleration due to gravity is greatest for the elephant.
- Both elephant and feather have the same force of gravity, yet the feather experiences greater air resistance.
Which of the above statements is/are correct?
[A] Only 2 statements are correct
[B] Only 1 statement is correct
[C] Only 3 statements are correct
[D] All statements are correct
Show Answer
Correct Answer: B [Only 1 statement is correct]
Notes:
Of the given statements, only statement 4 is correct: Both elephant and feather experience the same gravitational acceleration, but because of its relatively larger surface area for its mass, the feather experiences greater air resistance. The force of gravity is greater for the elephant (due to higher mass), and acceleration due to gravity remains constant for both objects irrespective of mass.
23. Which of the following statements is/ correctly matched?
- Origin of the Universe – Nebular Hypothesis
- Evolution of the Earth – The Big Bang theory
- Evolution of the Moon – The Big Splat Theory
select the the correct options from the code given below:
[A] 1, 2 & 3
[B] 1 & 3
[C] Only 1
[D] Only 3
Show Answer
Correct Answer: D [Only 3]
Notes:
The correct match is
Origin of the Universe – Big Bang Theory
Evolution of the Earth – Nebular Hypothesis
Evolution of the moon – The Big Splat
24. Which among the following statements is/are correctly matched?
- Sial – continental crust
- Sima – oceanic crust
Select the correct code from the options given below:
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 & 2
Show Answer
Correct Answer: C [Both 1 & 2]
Notes:
Sial is composed of Silica and Aluminium. It is found in the continental crust. Sima is composed of Silica and Magnesium. It is found in the oceanic crust.
25. Which of the following statements is/are correct?
- The specific heat of land is more than that of water.
- Diurnal and annual range of temperatures are least in oceans.
Select the correct code from the options given below:
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: B [Only 2]
Notes:
The specific heat of water is higher than that of land, meaning water requires more heat to raise its temperature. As a result, oceans, due to their high specific heat and mixing of water, have the least diurnal and annual temperature ranges. Thus, statement 1 is incorrect and statement 2 is correct.
26. According to the International Astronomical Union (IAU), which of the following are conditions for a celestial body to be classified as a planet?
- It must be spherical.
- It must orbit a star.
- It must not share its orbital zone with other objects of similar size.
Select the correct answer using the codes given below:
[A] Only 1 & 2
[B] Only 2 & 3
[C] Only 1 & 3
[D] 1, 2 & 3
Show Answer
Correct Answer: D [1, 2 & 3]
Notes:
IAU defines a planet as a celestial body that (1) orbits a star, (2) is sufficiently massive for its self-gravity to assume a nearly round shape (spherical), and (3) has cleared its neighborhood around its orbit, i.e., it does not share its orbital zone with other objects of comparable size.
27. Consider the following statements about the IceCube Neutrino Observatory:
- The IceCube telescope is a powerful tool to search for dark matter.
- IceCube studies the neutrons.
- The IceCube Neutrino Observatory is constructed at the Amundsen–Scott South Pole Station in Antarctica.
Which of the statements given above is/are correct?
[A] Only 3
[B] Only 1 and 2
[C] 1, 2 and 3
[D] Only 1 and 3
Show Answer
Correct Answer: D [Only 1 and 3]
Notes:
Statements 1 and 3 are correct. The IceCube telescope is a powerful detector that investigates dark matter and is located at the Amundsen–Scott South Pole Station in Antarctica. Statement 2 is incorrect as IceCube studies neutrinos, not neutrons. It detects astrophysical neutrinos, not other subatomic particles such as neutrons.
28. Which of the following precautions should be taken while using a scale?
- The scale should be placed parallel to the object.
- The eye should not be placed vertical while reading.
Select the correct answer from the codes given below:
[A] Only 1
[B] Only 2
[C] Both 1 and 2
[D] None of the above
Show Answer
Correct Answer: A [Only 1]
Notes:
The scale must be placed parallel to the object being measured to ensure accuracy. The eye should be placed vertically above the scale mark for correct reading and to avoid parallax error. Therefore, statement 1 is correct, but statement 2 is incorrect.
29. Which of the following statements is/are correct about laboratory thermometer?
- Size is larger than clinical thermometer.
- Range is 35-42 degree Celsius.
- It is cylindrical in shape.
- It has straight capillary.
Select the correct answer from the codes given below:
[A] Only 1, 2, 3, and 4
[B] Only 1, 2, and 3
[C] Only 1, 3, and 4
[D] Only 2, 3, and 4
Show Answer
Correct Answer: C [Only 1, 3, and 4]
Notes:
A laboratory thermometer is much larger than clinical thermometer. Its temperature range is 0-100 degree Celsius. Its bulb remains in contact with the substance or body. The design of body is simple and cylindrical. It has a straight capillary and thermometric liquid is mercury.
30. Which of the following are requirements for producing fire?
- Fuel
- Air
- Heat
Select the correct answer from the codes given below:
[A] Only 1 and 2
[B] Only 1 and 3
[C] Only 2 and 3
[D] All of the above
Show Answer
Correct Answer: D [All of the above ]
Notes:
The essential requirements for producing fire are: fuel, air (to supply oxygen) and heat (to raise the temperature of the fuel beyond the ignition temperature).
