Railway Science (Physics-Units and Measurements)

(In honour of James Watt, the eighteenth-century developer of the steam engine). Power is the amount of energy consumed per unit of time. The power unit is Joule per second (J/s). 1 horsepower = 746 watt, Temperature - kelvin(K), Current - ampere(A), voltage (potential difference) - volt(V).

Cyclotron - measures small magnitude Cyclones. Cyclotron is a device used to accelerate charged bodies to very high velocities using crossed electric and magnetic fields. It was invented to investigate the nuclear structure by E.O Lawrence and M.S Livingston in 1934. Both electric and magnetic fields are used in the cyclotron to increase the energy of the charged particles. The cyclotron consists of an electromagnet, a vacuum chamber, and two accelerating electrodes connected to a source of alternating voltage.

The accepted average calorie requirement in India is 2400 calories per person per day in rural areas and 2100 calories per person per day in urban areas.

Force is defined as the rate of change of momentum. For an unchanging mass, this is equivalent to mass × acceleration. So, 1 N (newton) = 1 kg m s⁻² , or 1 kg m/s². Work = force × displacement. So, SI units of work are Kg m/sec² , Newton-meter and Joule.

The curie (Ci) - A non-SI unit of radioactivity originally defined in 1910. One curie is equal to 37 billion Bequerels. Rutherford (father of nuclear physics) - An obsolete unit of radioactivity which was superseded by the introduction of the becquerel in 1975. SI Units: Electrical capacitance - Faraday (F).

Ozone layer - Average thickness is about 300 Dobson Units or a layer that is 3 millimeters thick. Sievert unit (Sv) - Used to quantify the biological effects of ionizing radiation.

It was Invented by William Gilbert. Ampere meter - An instrument for measuring either direct or alternating electric current. Multimeter - A measuring instrument that can measure multiple electrical properties (voltage, resistance, and current). Ohmmeter - An electrical instrument used to measure resistance in a circuit or component.

Ammeter - Used to measure the current flowing through the circuit. It has low resistance, ideally zero. Voltmeter - Used to measure the voltage across two terminals in a circuit. It ideally has infinite resistance. Voltmeter is connected in parallel.

The force acting perpendicular to the surface of the object is called thrust. The effect of thrust is more on the smaller surface area than the thrust acting on a larger surface area. Thrust Force (FT) = Pressure (P) × Area (A). SI units :
Pressure - pascal, Momentum - 𝑘𝑔𝑚/𝑠 , Surface tension - 𝑁/𝑚

The distance travelled by a wave in one second is called its wave velocity. It is a vector quantity. Wave velocity = frequency (f) × lamda (λ).