Transmission of Heat(ऊष्मा का संचरण)|Humidity(आद्रता)|Electricity(विघुत धारा)|Summary

Heat(ऊष्मा )|Summary

Heat (ऊष्मा)-Humidity & Relative Humidity(आर्द्रता और आपेक्षिक आर्द्रता)|Current Electricity (विद्युत धारा)|OMR

Evaporation(वाष्पीकरण)|Humidity(आर्द्रता )|Absolute Humidity(निरपेक्ष आर्द्रता)|Relative Humidity(सापेक्षिक आर्द्रता)|Condensation(संघनन )|Form Of Condensation(संघनन का रूप)|Fog & Mist(कोहरा धुध)|Clouds(बादल )|Precipitation(वर्षण)|Rainfall(वर्षा)|Summary

Calorimetry(ऊष्मा मापन )|Heat Transfer(ऊष्मा स्थानांतरण)|Questions(प्रश्न )|OMR|Summary

Mode Of Heat Transfer (ऊष्मा संचरण की विधियाँ)|Conduction (चालन)|Conduction In Steady State (स्थाई अवस्था में चालन) |OMR

Thermodynamics(ऊष्मा गतिकी )|Zeroth Law Of Thermodynamics(ऊष्मप्रवैगिकी का ज़ीरोथ नियम)|First Law of Thermodynamics(ऊष्मप्रवैगिकी का पहला नियम)|Thermodynamics Process(ऊष्मप्रवैगिकी प्रक्रिया)|Questions(प्रश्न )|OMR|Summary

Heat (ऊष्मा)|Temperature(ताप) |Thermometer (तापमापी)|Transmission Of Heat (गर्मी का संचरण)|OMR

Basic चर्चा |उदाहरण|धारा |विमा |धारा धनत्व का मात्रक |OMR|Summary

Thermodynamics- Heat And Temperature(उष्मागतिकी - ऊष्मा और तापमान)|OMR|Summary

Read the following text and answer the following questions on the basis of the same: At power plant, a transformer increases the voltage of generated power by thousands of volts so that it can be sent of long distances through high-voltage transmission power lines. Transmission lines are bundles of wires that carry electric power from power plants to distant substations. At substations, transformers lower the voltage of incoming power to make it acceptable for high volume delivery to nearby end-users. Electricity is sent at extremely high voltage because it limits so-called line losses. Very good conductors of electricity also offer some resistance and this resistance becomes considerable over long distances causing considerable loss. At generating station, normally voltage is stepped up to around thousands of volts. Power losses increase with the square of current. Therefore, keeping voltage high current becomes low and the loss is minimized. Another option of minimizing loss is the use of wires of super-conducting material. Super-conducting materials are capable of conducting without resistance, they must be kept extremely cold, nearly absolute zero, and this requirement makes standard super-conducting materials impractical to use. However, recent advances in super-conducting materials have decreased cooling requirement. In Germany recently 1 km super-conducting cable have been installed connecting the generating station and the destination. It has eliminated the line loss and the cable is capable of sending five times more electricity than conventional cable. Using super-conducting cables Germany has also get rid of the need of costly transformers. Transformers generate waste heat when they are in operation and oil is the coolant of choice. It transfers the heat through convection to the transformer housing, which has cooling fins or radiators similar to heat exchangers on the outside. Flush point is a very important parameter of transformer oil. Flashpoint of an oil is the temperature at which the oil ignites spontaneously. This must be as high as possible (not less than 160^(@)C from the point of safety). Fire point is the temperature at which the oil flashes and continuously burns. This must be very high for the chosen oil (not less than 200^(@)C ). Flush point of an oil is