Physics

One atomic mass unit (AMU) is defined as exactly 1.66 x 10^-27 kilograms. The other options are incorrect or inconsistent with this standard value.

Dimensional analysis is used to derive possible formulas by ensuring dimensional consistency and to check the homogeneity of physical equations, confirming that all terms have the same dimensions. It is not typically used for verification of laws, which requires experimental validation.

Nuclei with the same mass number but different atomic numbers are called isobars. Isotopes have the same atomic number but different mass numbers, isotones have the same number of neutrons, and isomers are nuclei with the same atomic and mass numbers but different energy states.

When subtracting two measurements, the total uncertainty is the sum of their absolute uncertainties because uncertainties add regardless of whether quantities are added or subtracted.

A beta particle is an electron emitted during beta decay, which carries a charge of -1 elementary charge.

Torque is the rotational equivalent of force and causes angular acceleration in a body. It does not directly cause linear acceleration or determine the direction of motion.

The SI unit of torque is the newton-meter (N·m), which represents a force applied at a distance. Although joule (J) has the same units (N·m), it represents energy, not torque, so option A is correct.

Alpha particles have much lower penetration power compared to beta particles because they are heavier and carry a double positive charge, causing them to lose energy quickly in matter. Typically, alpha particles penetrate only a few centimeters in air, whereas beta particles penetrate much further, making alpha particle penetration about 10 times less than beta particles.

Beta particles are lighter and carry a single charge compared to alpha particles, which are heavier and doubly charged. Because beta particles have lower ionizing power, they lose less energy in collisions and thus have greater penetration power than alpha particles.

Absolute uncertainty refers to the margin of error or the smallest unit that can be measured reliably by an instrument, which is typically related to the least count of the instrument. It does not depend on the magnitude of the measurement or the percentage error, which are related to relative uncertainty. Therefore, absolute uncertainty depends primarily on the least count of the instrument.