Physics

Charles Algernon Parsons invented the steam turbine in 1884, which greatly improved the efficiency of steam engines. The other options are unrelated to the invention of the steam turbine.

Dr. Abdus Salam was a renowned Pakistani physicist who worked in theoretical physics and had connections with prominent scientists including Albert Einstein's circle. He is the most famous Pakistani scientist associated with Einstein's work. Riazuddin Siddiqui was also a notable Pakistani physicist but did not work directly under Einstein.

A dyne is the unit of force in the centimeter-gram-second (CGS) system. It is defined as the force required to accelerate a mass of one gram at a rate of one centimeter per second squared.

The Uncertainty Principle was formulated by Werner Heisenberg, which states that certain pairs of physical properties cannot both be known to arbitrary precision simultaneously.

Cadmium is commonly used in control rods because it is an excellent neutron absorber, which helps regulate the rate of nuclear fission in a reactor. Graphite and heavy water act as moderators, not control rods, so they do not control the reaction by absorbing neutrons.

One mega ohm (MΩ) is equal to 10^6 ohms, which means one million ohms. This is a standard unit conversion in electrical resistance. Among the options given, option A (10^6 ohm) correctly represents one mega ohm. The original correct answer was C (10^7 ohm), which is incorrect. Therefore, the correct answer is option A.

When a bullet penetrates a target, the kinetic energy of the bullet is converted primarily into mechanical energy, which causes deformation and damage to the target. However, a significant portion of the kinetic energy is also converted into heat energy due to friction and impact. Therefore, both mechanical energy and heat energy are produced during the penetration process, making option C ('Both B&D') the most accurate answer.

Communication satellites are typically placed in geostationary orbit, which is a specific type of geosynchronous orbit where the satellite remains fixed over one point on the Earth's equator, making option C correct. Geosynchronous orbit (option A) is a broader category that includes geostationary but also other orbits with the same period as Earth's rotation but different inclinations or eccentricities. Semi synchronous orbits (option B) are used for other purposes like GPS satellites, not communication satellites.

A dioptre is a unit of measurement for the optical power of a lens or curved mirror, defined as the reciprocal of the focal length measured in meters. It is not related to luminous intensity, general power, or astronomical distances.

The antiparticle of an electron is called a positron, which has the same mass as an electron but a positive charge. This makes option A the correct answer.