Physics

The SI unit of frequency is the hertz (Hz), which represents one cycle per second. Other options like vibration s⁻², radian, and ms⁻¹ are units for different physical quantities.

One light year is the distance that light travels in one year in vacuum. It is exactly 9.46073 × 10^15 meters, which is equivalent to about 9.46073 × 10^12 kilometers (approximately 9.46 trillion kilometers). Therefore, the correct option must have the unit meters with the value close to 9.5 × 10^15. Option A correctly states 9.5 × 10^15 meters, which is the closest and accurate representation of one light year. Option C incorrectly states 9.5 × 10^15 kilometers, which is off by a factor of 1000. Hence, the correct answer is A.

An ideal fluid is a theoretical concept in fluid mechanics that is non-viscous, incompressible, and exhibits steady flow, meaning it possesses all these properties simultaneously. Therefore, option D correctly states that an ideal fluid possesses all these properties.

After completing two full revolutions around a circle, the displacement (straight-line distance from start to end point) is zero because the starting and ending points coincide. However, the path length covered is the circumference times two. Thus, the ratio of displacement to path length is 0.

When a length is measured as 6200 mm with a meter rod, which typically has precision to the nearest millimeter or centimeter, the trailing zeros without a decimal point are not considered significant. Thus, the number 6200 has 2 significant figures (6 and 2).

The period T of a circular motion is the time taken to complete one full revolution. It is given by the circumference of the circle (2πr) divided by the speed v, hence T = 2πr/v.

In simple harmonic motion, the velocity of the particle is maximum as it passes through the mean position because all the potential energy is converted into kinetic energy there. At the extreme positions, the velocity is zero as the particle changes direction.

A carburettor uses the Venturi effect to reduce pressure and draw fuel into the air stream, which is explained by Bernoulli's equation. Therefore, both the Venturi meter principle and Bernoulli's equation apply to the carburettor's operation.

Isaac Newton formulated the inverse square law of gravitation, which states that the gravitational force between two masses is inversely proportional to the square of the distance between them. This fundamental law is a cornerstone of classical physics.

The seconds hand of a watch completes one full rotation, which is 2π radians, in 60 seconds. Therefore, its angular speed is given by the total angle divided by the time taken: ω = 2π / 60 = π/30 radians per second. This matches option C. The original correct_answer field was incorrectly set to D, but the explanation correctly identified the answer as π/30 radians per second, which corresponds to option C.