1. Consider the following statements regarding the elementary particle “Neutrino” and its antiparticle “Antineutrino”:
- Neutrino has a positive electric charge, while antineutrino has a negative electric charge.
- Both neutrino and antineutrino have zero mass.
Which of the above statements is/are correct?
[A] Neither 1 nor 2
[B] Only 1
[C] Only 2
[D] Both 1 and 2
Show Answer
Correct Answer: A [Neither 1 nor 2]
Notes:
Both statements are incorrect. Neutrinos and antineutrinos are electrically neutral and possess no charge. They do not have exactly zero mass; experimental evidence suggests their masses are extremely small, but not zero. The primary distinctions involve lepton number and helicity, not electric charge or precisely zero mass.
2. Consider the following statements:
- If there were no atmosphere, the Sun would appear white, and the sky would appear black.
- If the Earth were to stop rotating on its axis, the oceans would migrate toward the poles.
Which of the above statements is / are correct?
[A] Only 1
[B] Both 1 and 2
[C] Only 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: B [Both 1 and 2]
Notes:
Statement 1 is correct because the Earth’s atmosphere scatters sunlight, giving the sky its blue color; without it, the sky appears black and the Sun looks white. Statement 2 is also correct; the Earth’s rotation causes an equatorial bulge through centrifugal force. If rotation ceased, this force would vanish and oceans would migrate toward the poles due to gravity.
3. Consider the following statements:
- Titan is the largest moon of Jupiter and is the only known moon to have a magnetic field
- Ganymede is the largest moon of Saturn and is the only moon to have a dense atmosphere
Which of the above statements is/are correct?
[A] 1 Only
[B] 2 Only
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: D [ Neither 1 nor 2]
Notes:
- “Titan is the largest moon of Jupiter and is the only known moon to have a magnetic field”: This statement is incorrect on both counts. Titan is not a moon of Jupiter; it is a moon of Saturn. Titan is indeed the largest moon of Saturn and is known for having a thick atmosphere rich in nitrogen, along with lakes and rivers of liquid hydrocarbons on its surface. However, Titan does not have a significant magnetic field.
- “Ganymede is the largest moon of Saturn and is the only moon to have a dense atmosphere”: This statement is partially correct and partially incorrect. Ganymede is not a moon of Saturn; it is a moon of Jupiter. Ganymede is indeed the largest moon in the entire solar system, and it’s one of the Galilean moons of Jupiter. It is also the only moon known to have its magnetic field. However, Ganymede does not have a dense atmosphere. It has a very thin atmosphere composed mainly of oxygen, but it’s not considered dense compared to Earth’s atmosphere.
Correct information is as follows:
- Titan is the largest moon of Saturn, not Jupiter. It does not have a magnetic field.
- Ganymede is the largest moon of Jupiter and does have a magnetic field, but it does not have a dense atmosphere.
4. Consider the following differences between Redshift and Blueshift:
- While redshift occurs when light source moves away from an observer, blueshift occurs when light source moves towards the observer
- While in redshift is characterized by increase in wavelength, blueshift is characterized by a decrease in wavelength
Which of the above statements is/are correct?
[A] 1 Only
[B] 2 Only
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: C [ Both 1 & 2]
Notes:
Both are correct statements
A redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. Similarly, blueshift occurs when radiation from an object is decreased in wavelength and the light source moves towards the observer.
5. Which of the following statements with respect to the Thorium based nuclear fuel cycle is/are correct?
- Thorium based nuclear cycle produces little or no plutonium.
- To get criticality, Thorium based fuel cycle does not need any fissile isotopes.
- Thorium based nuclear cycle produces no hazardous wastes.
Select the correct option from the codes given below:
[A] Only 1 & 2
[B] Only 1
[C] Only 1 & 3
[D] 1, 2 & 3
Show Answer
Correct Answer: B [Only 1]
Notes:
Thorium fuel cycle produces little or no plutonium. However, to achieve criticality, external fissile isotopes like uranium-235 or plutonium are required as thorium-232 is not fissile. It does not eliminate hazardous waste but reduces long-lived transuranic elements. Thus, only statement 1 is correct.
6. Consider the following statements regarding real and virtual images:
- Real images can be obtained on a screen, whereas virtual images cannot be obtained on a screen.
- Real images are always inverted, and virtual images are always erect.
Which of the above statements is/are correct?
[A] Only 1
[B] Both 1 and 2
[C] Only 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: B [Both 1 and 2]
Notes:
Statement 1 is correct as real images can be projected on a screen, while virtual images cannot. Statement 2 is also correct, since real images are always inverted and virtual images are always erect. Therefore, both statements given are accurate descriptions of image formation in optics.
7. Consider the following statements regarding Alpha, Beta, and Gamma radiations:
- Alpha particles exhibit the highest ionizing power but the lowest penetrating ability among the three.
- Gamma rays possess the greatest penetration power but the lowest ionizing ability.
Which of the above statements is/are correct?
[A] Only 1
[B] Only 2
[C] Neither 1 nor 2
[D] Both 1 and 2
Show Answer
Correct Answer: D [Both 1 and 2]
Notes:
Alpha particles, being heavy and doubly charged, easily ionize surrounding matter but can be stopped by a sheet of paper or a few centimeters of air. Gamma rays, as electromagnetic waves, penetrate several centimeters of lead yet interact minimally with matter, hence have the lowest ionizing power. Thus, both statements are correct as per radiation physics.
8. Consider the following statements regarding the moderators used in nuclear reactions:
- Both normal water and heavy water can be utilized as moderators in nuclear reactions.
- Moderators are employed in both nuclear reactors and nuclear bombs.
Which of the above statements is/are correct?
[A] Only 1 is correct
[B] Only 2 is correct
[C] Both 1 and 2 are correct
[D] Neither 1 nor 2 is correct
Show Answer
Correct Answer: C [Both 1 and 2 are correct]
Notes:
A moderator reduces the velocity of fast neutrons, making nuclear chain reactions possible with fissile materials like uranium-235. Both normal (light) water and heavy water are widely used as moderators in reactors, while graphite and beryllium are also used. Moderators are necessary for nuclear reactors and have been utilized in nuclear bomb designs as well.
9. Consider the following statements regarding the properties of sound:
- Low pitch sound has low frequency, whereas high pitch sound has high frequency.
- Soft sound has small pitch, and louder sound has large pitch.
Which of the above statements is / are correct?
[A] Only 1
[B] Only 2
[C] Neither 1 nor 2
[D] Both 1 and 2
Show Answer
Correct Answer: A [Only 1]
Notes:
Statement 1 is correct: pitch is directly related to the frequency of sound waves; low pitch corresponds to low frequency and high pitch to high frequency. Statement 2 is incorrect: softness and loudness depend on amplitude, not pitch. Thus, soft or loud sounds may have any pitch based on their frequency, not their amplitude.
10. Which of the following phenomena play a role in the formation of a rainbow?
- Dispersion
- Total Internal Reflection
- Refraction
Select the correct option from 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:
Rainbow formation involves dispersion (splitting of sunlight into spectrum), refraction (bending of light entering and leaving rain drops), and total internal reflection (light reflects inside the drop). All three phenomena are essential for the appearance and colors of the rainbow. Thus, options 1, 2, and 3 are all correct.
