The principle of conversation of energy: Energy is the capacity, or ability, to do work. The unit of energy is the joule. 1) Mechanical energy is converted to electrical energy by a generator (ii) Electrical energy is converted to mechanicalenergy by a motor (iii) Heat energy is converted to mechanical energy by a steam engine …
What is Magnetic flow meter: The flow rate of fluids that conduct electricity, such as water or molten metal, can be measured using an electromagnetic flowmeter whose principle of operation is based on the laws of electromagnetic induction. When a conductor of length L moves at right angles to a magnetic field of density B …
Formulas for mechanical engineering principles: Stress=Force/ cross sectionalarea s = F/APa Strain = change in length/length e = x/L Young’s modulus of elasticity = stress strain E = s/ε Pa Stiffness = force/extension k = F/δ. N/m Modulus of rigidity = shear stress/shearstrain G = t/γ Pa Thermal strain = coefficient of linear expansion × …
Thermistor: A thermistor is a semi-conducting material such as mixtures of oxides of copper, manganese, cobalt, etc. in the form of a fused bead connected to two leads. As its temperature is increased its resistance rap- idly decreases. Typical resistance/temperature curves for a thermistor and common metals are shown in figure below. The resistance of …
Dalton’s law of partial pressure states: the total pressure of a mixture of gases occupying a given volume is equal to the sum of the pressures of each gas, considered separately, at constant temperature. The pressure of each constituent gas when occupying a fixed volume alone is known as the partial pressure of that gas. …
A simple anemometer consists of a small piece of wire which is heated with the help of an electric current passing through it and this material is placed in the air or gas stream whose velocity is to be measured. When the stream passing through it the wire cools it, the rate of cooling being …
What is a pressure? The pressure acting on a surface is defined as the perpendicular force per unit area of surface. The unit of pressure is the pascal, Pa, where 1 pascal is =1 newton per square metre. Thus pressure, p = F/A pascals where F is the force in newtons acting at right angles …
Speed percentage problem. A drilling speed should be set to 400 rev/min. The nearest speed available on the machine is 412 rev/min. Calculate the percentage of over-speed. Solution: Percentage of over speed= available speed-correct speed/correct speed × 100% = 412-400/400 ×100% = 12/400 × 100% = 3%
Stress-Strain Problems and solutions: A wire of length 2.50 m has a per- centage strain of 0.012% when loaded with a tensile force. Determine the extension of the wire. Solution: Original length of wire = 2.50 m = 2500 mm and strain = 0.012 100 = 0.00012 Strain ε = extension/originallength =x/L, extension x = …