11. Which of the following statements regarding the image formed by a plane mirror are correct?
- The image is always virtual
- The distance of the image from the mirror is equal to the distance of the object from the mirror
- The image is laterally inverted
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:
The image formed by a plane mirror is always virtual, laterally inverted, and lies at a distance from the mirror equal to that of the object. The image is upright, equal in size, and cannot be projected on a screen, satisfying all the given statements.
12. Consider the following phenomena:
- Formation of a rainbow
- Dispersion of light
- A coin appears raised when placed in a trough filled with water
Which of the above involve refraction?
[A] Only 1 and 2
[B] Only 2 and 3
[C] 1, 2 and 3
[D] Only 1 and 3
Show Answer
Correct Answer: C [1, 2 and 3]
Notes:
All three—rainbow formation, dispersion of light, and the apparent raising of a coin in water—involve the refraction of light, which is the bending of light rays as they pass from one medium to another with different optical densities. Each phenomenon depends on the altering of light’s path due to this effect.
13. With reference to the phenomenon of sky appearing blue and sunsets appearing red, consider the following statements:
- Shorter wavelengths scatter more easily than longer wavelengths in the atmosphere.
- When the Sun is close to the horizon, there is more scattering of red light.
Which of the above statements is / are correct?
[A] Only 1
[B] Only 2
[C] Both 1 and 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: C [Both 1 and 2]
Notes:
Scattering of light by atmospheric molecules is wavelength-dependent. Shorter wavelengths (blue) scatter more efficiently, making the sky appear blue. During sunrise and sunset, sunlight travels a longer atmospheric path, scattering shorter wavelengths away and allowing predominantly red light to reach the observer, making the Sun appear red.
14. Which among the following statements is/are correct?
- A sail boat can be propelled by air blown at the sail from a big fan attached to the boat.
- All types of waves exhibit diffraction.
- Potatoes, maize, barley, and rice can be used for commercial production of ethanol.
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: B [Only 2 & 3]
Notes:
Statement 1 is incorrect because a fan attached to the boat blowing air onto its own sail creates internal forces that cancel, resulting in no net movement. Statement 2 is correct; diffraction is a universal property of all types of waves. Statement 3 is correct because potatoes, maize, barley, and rice are all used commercially to produce ethanol.
15. Consider the following statements with respect to the basic properties of Electromagnetic Waves:
- All electromagnetic waves – regardless of frequency – travel at the speed of light through vacuum.
- All electromagnetic waves are deflected by electric or magnetic fields.
- The frequency of electromagnetic waves does not change when the medium through which the waves are propagating changes.
Which of the above statements is/are correct?
[A] Only 1 and 3
[B] Only 1 and 2
[C] Only 2 and 3
[D] 1, 2 and 3
Show Answer
Correct Answer: A [Only 1 and 3]
Notes:
Statements 1 and 3 are correct. All electromagnetic waves travel at the speed of light in vacuum, irrespective of frequency. Statement 2 is incorrect as electromagnetic waves are not deflected by electric or magnetic fields. Although the speed changes when entering a new medium, the frequency of electromagnetic waves remains constant across different media.
16. Consider the following statements regarding the speed of sound in solids:
- Strong bonds between atoms or molecules in solids contribute to higher sound velocity.
- Close packing of particles in solids enables faster transmission of sound waves.
- Lower elasticity in solids compared to liquids and gases is a factor in higher sound velocity.
- A well-defined and ordered arrangement of particles in solids aids the propagation of sound.
How many of the above statements are correct?
[A] Only 2
[B] Only 3
[C] All 4
[D] Only 1
Show Answer
Correct Answer: B [Only 3]
Notes:
Statements 1, 2, and 4 are correct. Sound travels faster in solids due to strong interatomic bonds, close particle packing, and an ordered arrangement. Statement 3 is incorrect—solids have higher, not lower, elasticity than liquids and gases, which further facilitates faster sound propagation. Thus, only three statements are correct.
17. In Physics, which of the following situations result in work being done?
- Brakes are applied to a moving vehicle and the vehicle stops
- A ball is projected vertically upward and comes back due to gravity
- A body moves in a circular path
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: A [Only 1 & 2]
Notes:
Work is done when a force causes displacement in its direction. In situations 1 and 2, force acts along or against displacement, resulting in negative work. In case 3, the force acts perpendicular to displacement in a circular path, leading to zero work done. Thus, only 1 and 2 result in work being done.
18. Consider the following electromagnetic waves:
- X-rays
- Infra-red rays
- Radio waves
- Gamma rays
- Microwaves
Which of the following represents the correct order of these waves in terms of increasing wavelength?
[A] 1, 4, 2, 3, 5
[B] 5, 4, 1, 2, 3
[C] 4, 1, 5, 2, 3
[D] 4, 1, 2, 5, 3
Show Answer
Correct Answer: D [4, 1, 2, 5, 3]
Notes:
Electromagnetic waves in order of increasing wavelength are: gamma rays, X-rays, infra-red rays, microwaves, and then radio waves. Gamma rays have the shortest wavelength, followed by X-rays, then infrared, then microwaves, while radio waves possess the longest wavelengths. This order is crucial in distinguishing between these forms of radiation within the electromagnetic spectrum.
19. Consider the following properties of magnetic lines of force:
- They are closed continuous curves
- They travel from north to south outside the magnet and from south to north inside the magnet
- They bend along the length of the magnet
- They mutually repel each other
- They never intersect each other
Which of the above statements is / are correct?
[A] Only 1 and 2
[B] Only 1, 2 and 3
[C] Only 1, 2, 3 and 5
[D] 1, 2, 3, 4 and 5
Show Answer
Correct Answer: D [1, 2, 3, 4 and 5]
Notes:
All five statements correctly describe the properties of magnetic lines of force. They form closed continuous curves and travel outside from north to south, and inside from south to north. They bend along the length of the magnet, mutually repel, and never intersect each other, which are fundamental characteristics observed in magnetic field lines.
20. Consider the following statements:
- A circular metallic disc has a circular hole at its centre. When the disc is heated, the diameter of the hole will decrease.
- A common fluorescent tube contains mercury vapour at high pressure.
Which of the above statements is / are correct?
[A] Only 1
[B] Neither 1 nor 2
[C] Only 2
[D] Both 1 and 2
Show Answer
Correct Answer: B [Neither 1 nor 2]
Notes:
When a metallic disc with a central hole is heated, the entire disc—including the hole—expands, so the diameter of the hole increases, not decreases. A fluorescent tube contains low-pressure mercury vapor, not high-pressure vapor; typically, the vapor pressure is far below atmospheric pressure. Thus, both statements are incorrect.
