Tag: science & technology

Focal length measures the distance from the lens's optical center to the focal point where light converges. Distance is measured in meters (m) in SI units. m/s is velocity, m^-1 is diopter (used for lens power), and m² is area.

Moment of inertia measures an object's resistance to rotational acceleration, calculated as I = Σmr². Mass is in kg and radius squared is in m², giving kg·m². m/s² is acceleration and N is force.

Capacitance measures a capacitor's ability to store charge per unit voltage (C = Q/V). The SI unit for capacitance is the farad (F), named after Michael Faraday. Ohm is the unit of resistance.

Stress is defined as force per unit area (σ = F/A). Force is measured in Newtons (N) and area in m², giving the unit N/m², which is called Pascal (Pa). Stress is not simply measured in Newtons.

Luminous intensity is a base quantity in the SI system. Its unit is the candela (cd), which is one of the seven SI base units. The spelling 'candela' is correct.

Torque measures rotational force and is calculated as τ = r × F (radius × force). Force is in Newtons (N) and radius in meters (m), giving the unit N·m. J/s is power (watt).

The average human blinks approximately 12-15 times per minute. Blinking helps lubricate and clean the eyes. This rate can vary with activities like reading or screen use.

A normal resting pulse rate for adults is 60-100 beats per minute. This range represents healthy cardiovascular function. Rates above 100 (tachycardia) or below 60 (bradycardia) at rest may indicate medical conditions.

The normal resting heart rate for adults is 60-100 beats per minute, making option A correct. Heart rate varies with age, fitness level, and activity. Rates above 100 bpm (tachycardia) or below 60 bpm (bradycardia) at rest may indicate medical conditions.

Children have naturally faster heart rates than adults. The normal resting pulse rate for children is 70-100 beats per minute, while adults average 60-100 bpm. Option A is the adult range, and the other ranges are too narrow or incorrect.