Name the device used to increase the voltage at a generating station.

Name the device used to decrease the voltage at the sub station for its supply.

The teachers of Geeta's school took the students on a study tirp to a power generating station, loactad nearly 200km away form the city.The teacher explained that electrical energy is transmitted over such a long distance to their city, in the form of alternating current (ac) raised to a high voltage. At the receiving end is the city, the voltage is reduced to operate the devices. As a result, the power loss is reduced. Geeta listened to the teacher and asked question about how the ac is converted to a higher or lower voltage. (a) Name th device used to change the alternating to a higher or lower value. State one cause for power dissipation in this device. (b) Explain with an example, how power loss is reduced if the energy is transmitted over long distance as an alternating current rather than a direct current, (c) Write two values each shown by the teachers and Geeta.

Modem is a device used for

The device used to hear heartbeats is called a

(a) Draw the diagram of a device which is used to decrease high S voltage into a AC voltage and state its working principle. Write four sources of energy loss in this device. (b) A small town with a demand of 1200 kW of electric power at 220 V is situated 20 Km away from an electric plant generating power at 440V. The resistance of the two wire line carrying power is 0.5 Omega per km. The town gets the power from the line through a 4000-220 V step-down transformer at s sub-station in the town. Estimate the line power loss in the from of heat.

At what voltage and frequency is the electric power generated at the power generating station ?

Name the device used to protect the electric circuits from overloading and short circuits.

Name two devices which are used to measure the volume of an object.

Name the device used to protect the electric circuits from overloading and short circuits. On what effect of electricity does the above device work ?

A device used to measure very high temperature is