1. A rocket is not a projectile until its
A rocket is not considered a projectile until its propellant fuel is burnt. Before the fuel is burned, it is still in the process of launching and accelerating, whereas once the fuel is burnt and the rocket is no longer generating thrust, it becomes a projectile, continuing its motion due to inertia and gravity.
2. The geocentric theory is given by
The geocentric theory, which suggests that Earth is at the center of the universe and all other celestial bodies revolve around it, was proposed by the ancient Greek astronomer Ptolemy.
3. The angle of projection for a projectile to cover maximum range is
For a projectile to cover the maximum range, the angle of projection should be 45°. At this angle, the horizontal and vertical components of velocity are optimized, giving the projectile the farthest distance.
4. The air resistance on freely failing body depends upon
The air resistance (or drag force) on a freely falling body depends on the shape, size, and speed of the object. A body with a larger surface area or irregular shape experiences more air resistance compared to a streamlined object. While pressure and density can also influence air resistance, the primary factor is the shape of the object.
5. The centripetal force required for a car to bicyle to go round a circular
curve depends on
The centripetal force required for a vehicle to go around a circular curve depends on both the speed of the vehicle and the radius of the curve. The formula for centripetal force is:
F = mv sq / r
where:
• m is the mass of the vehicle,
• v is the speed of the vehicle,
• r is the radius of the curvature.
This shows that the force is directly proportional to the square of the speed and inversely proportional to the radius of the curve.
6. A rocket is not a projectile until its
A rocket is not considered a projectile until its propellant fuel is burnt. This is because the rocket's motion depends on the expulsion of exhaust gases, which generates thrust. The combustion of propellant fuels is what propels the rocket, making it a powered vehicle, unlike a projectile, which relies solely on initial velocity and gravity.
7. The geocentric theory is given by
The geocentric theory, which states that the Earth is at the center of the universe and all celestial bodies revolve around it, was formulated by the ancient Greek astronomer Claudius Ptolemy. This theory was widely accepted until the heliocentric model proposed by Copernicus came into prominence.
8. The centripetal force required for a car to bicyle to go round a circular
curve depends on
The centripetal force required for a vehicle (car or bicycle) to go around a circular curve depends on two factors:
Speed (v) of the vehicle: The faster the vehicle moves, the greater the centripetal force required.
Radius of curvature (r): A smaller radius (sharper curve) requires a larger centripetal force.
The formula for centripetal force is:
Fc = mv sq / r
Where:
m is the mass of the vehicle,
v is the speed,
r is the radius of the curve.
9. The air resistance on freely failing body depends upon
The air resistance (also called drag) acting on a freely falling body depends on several factors, but shape plays a key role. The shape of the object affects how it interacts with air particles as it moves through the atmosphere.
In addition to shape, the air resistance also depends on:
Density of the air (D): Air resistance is greater in denser air.
Speed of the object (v): Higher speed leads to more air resistance.
10. The angle of projection for a projectile to cover maximum range is
For a projectile, the maximum range is achieved when the angle of projection is 45° (assuming no air resistance). This angle balances the vertical and horizontal components of velocity, giving the projectile the greatest distance.
11. The strongest force in nature is:
The strongest force in nature is the nuclear force. It binds protons and neutrons together in the atomic nucleus. It is much stronger than gravity, electromagnetism, and electrostatic force.
12. The wavelength of the matter waves is independent of:
The wavelength of matter waves, according to de Broglie’s theory, is independent of charge. It is determined by the particle's mass and velocity, not its charge or electromagnetic properties.
13. Neutron was discovered by:
Neutron was discovered by James Chadwick in 1932. His discovery provided insights into the structure of the atom, revealing the presence of neutral particles (neutrons) alongside protons and electrons.
14. In nuclear reaction, there is conservation of
In a nuclear reaction, mass, energy, and momentum are conserved. This principle ensures that the total energy, mass, and momentum before and after the reaction remain the same according to physical laws.
15. The principle on which a hydrogen bomb works is:
A hydrogen bomb operates on the principle of nuclear fusion, where lighter atomic nuclei, such as hydrogen, fuse to form heavier nuclei, releasing vast amounts of energy, much like the sun’s process.
16. Isotopes have the same:
Isotopes have the same atomic number, meaning they belong to the same element and have the same number of protons. However, they differ in the number of neutrons and atomic mass.
17. A good moderator should:
A good nuclear moderator should absorb neutrons, have a low atomic number, and be stable at high temperatures. These properties help slow down neutrons efficiently without absorbing too many.
18. The dual nature of light is exhibited by:
The dual nature of light is demonstrated through diffraction (wave-like behavior) and the photoelectric effect (particle-like behavior). These phenomena highlight that light exhibits both wave and particle properties.
19. The main source of solar energy is:
The main source of solar energy is nuclear fusion. In the Sun's core, hydrogen atoms fuse to form helium, releasing vast amounts of energy in the process, which powers the Sun.
20. The important conclusion given by Millikan’s experiment about charge is:
Millikan's oil drop experiment concluded that charge is quantized. It showed that electric charge exists in discrete amounts, with the charge of an electron being the fundamental unit of charge.
21. Hydrogen bomb is based upon the principle of
The hydrogen bomb operates on the principle of nuclear fusion, where light atomic nuclei (like hydrogen) fuse to form heavier nuclei, releasing immense energy, similar to the process in the Sun.
22. In nuclear reaction, there is conservation of
In a nuclear reaction, the conservation of mass, energy, and momentum is observed. This principle ensures that the total mass, energy, and momentum remain constant before and after the reaction.
23. The strongest force in the nature is
The strongest force in nature is the nuclear force. It binds protons and neutrons in an atomic nucleus, and is significantly stronger than gravitational, magnetic, or electric forces at subatomic distances.
24. The wavelength of the matter waves is independent of
The wavelength of matter waves, described by de Broglie's equation, is independent of charge. It depends on the mass, velocity, and momentum of the particle, but not on its charge.
25. Neutron was discovered by
The neutron was discovered by James Chadwick in 1932. His experiment revealed the existence of a neutral subatomic particle in the nucleus, which was crucial for understanding atomic structure and nuclear reactions.
26. Kepler’s first law of planetary motion is also called
Kepler's first law of planetary motion, also known as the Law of Orbits, states that planets move in elliptical orbits with the Sun at one of the foci, not in perfect circles.
27. The molecular range is of the order of
The molecular range is typically of the order of 10⁻⁸ cm. This refers to the size scale of molecules, which are often measured in nanometers or fractions of micrometers.
28. The centripetal force around the circular path depends upon
The centripetal force required for an object to move in a circular path depends on its speed. It is directly proportional to the square of the speed and inversely proportional to the radius.
29. X Square = ky. This is the equation of a
The equation X square = 𝑘𝑦 represents a parabola. Irepresents a parabola. It is a quadratic equation in terms of
𝑦, where k is a constant, defining the shape and orientation of the parabola.
30. The Helio Centric theory is given by
The Heliocentric theory, proposed by Nicolaus Copernicus, suggests that the Sun is at the center of the solar system, with planets orbiting around it.
31. The scientists released the world’s smallest stop-motion film called ‘A Boy and His Atom’ by:
The world's smallest stop-motion film, A Boy and His Atom, was released by IBM. It was created using individual atoms, showcasing the potential of atomic manipulation for visual media.
32. Which country launched first ever deep UV laser device?
The first-ever deep UV laser device was launched by China. This groundbreaking technology operates at extremely short wavelengths and has significant potential for applications in science and technology.
33. NASA satellite data found freshwater losses during the past decade in:
NASA satellite data revealed significant freshwater losses in the Middle East over the past decade, highlighting concerns about water scarcity in the region.
34. The first complete bionic man of the world unveiled at London’s Science Museum called:
The first complete bionic man, called Rex, was unveiled at London's Science Museum. He was created as part of a project to showcase advancements in bionic technology.
35. NASA recently marked the 10th anniversary of the space shuttle disaster of:
NASA recently marked the 10th anniversary of the space shuttle disaster of Columbia, which tragically disintegrated upon reentry into Earth's atmosphere on February 1, 2003.
36. Which one of the following subjects is not related to ‘Robot’?
While hydraulics can be used in robotic systems for movement or control, it is not directly related to the core concept of robotics itself, which involves automation, artificial intelligence, and robotics as a whole.
37. The first 100 percent ultrasound toothbrush of the world developed by the scientists of:
The first 100 percent ultrasound toothbrush in the world was developed by scientists in the UK. This toothbrush uses ultrasonic technology for deep cleaning and efficient plaque removal.
38. India was affected by the cyber spying campaign called
India was affected by the cyber spying campaign called Red October. This campaign targeted various government and diplomatic institutions across the world, focusing on gathering sensitive data.
39. ISRO’s 100th space mission was completed by the launch of:
ISRO's 100th space mission was accomplished with the launch of PSLV-C21. This milestone marked a significant achievement in India's space exploration, demonstrating ISRO's progress in satellite launching capabilities.