measurement and SI units - Category wise Question and Answer Practice Test with Solutions

Answer: (b)

Acceleration is the correct answer.

Acceleration Definition:

the act or process of moving faster or happening more quickly: the act or process of accelerating or ability to accelerate

• It is the time rate of change of velocity of a body.
• It is a vector quantity.
• Its SI unit is m/s².

The correct explanation for the problem:

When the coin toss, it also has the same velocity as the velocity of the train but during the time, the coin is in the air, the velocity of the train keeps on increasing, and hence it falls behind the passenger.

Definition for other options,

Speed :

Speed is defined as the rate of change of position of an object in any direction. It is measured as the ratio of distance to the time in which the distance was covered. It is a scalar quantity as it has only direction and no magnitude

Deceleration :

A decrease in speed as the body moves away from the starting point is defined as Deceleration. Deceleration is the opposite of acceleration. Deceleration also is known as negative acceleration.

Velocity :

Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time. Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies.

Answer: (a)

The SI unit of force is the newton, symbol N.

Newton :

Newton, an absolute unit of force in the International System of Units (SI units), abbreviated N. It is defined as that force necessary to provide a mass of one kilogram with an acceleration of one metre per second per second.

Faraday : 

A faraday is a dimensionless unit of electric charge quantity, equal to approximately 6.02 x 10²³ electric charge carriers.

Fermi :

Fermi ('unit of measurement') is an SI unit of length equal to 10⁻¹⁵ metres, which means a quadrillionth of one metre. This distance is sometimes called a fermi and was so named in honour of Italian-American physicist Enrico Fermi, as it is a typical length-scale of nuclear physics.

Rutherford : 

The rutherford (symbol Rd) is a non-SI unit of radioactive decay. It is defined as the activity of a quantity of radioactive material in which one million nuclei decay per second. It is therefore equivalent to one megabecquerel, and one becquerel equals one microrutherford.

Answer: (a)

746 watts

A power level of 1 hp is approximately equivalent to 746 watts (W) or 0.746 kilowatts (kW). To convert from horsepower to watts, multiply by 746.

To convert from watts to horsepower, multiply by 0.00134.

Answer: (a)

The product of velocity and time if, the distance covered represents the area of the shaded portion.

Answer: (c)

Kilogram or Kilogram Force per Square Centimeter (kg/cm² or kgf/cm²) is a pressure unit that has been largely superseded by the SI unit system of pascal units.

It is the metric equivalent of pounds per square inch (psi). 1 kg/cm² equals 98,066.5 pascals.