26) Efficiency of a power transformer is in the order of

27) In a step down single phase power transformer, primary voltage is 22 kV and secondary voltage is 220V. When secondary is delivering a load current of 100 A, primary current is

28) What will be the copper loss at half load of a single phase transformer which is having a copper loss of 1000 W at full load?

29) Two dissimilar metals such as iron and copper are joined together to form a part of a device. When the junction is heated, a voltage will be developed across the open ends of the wires. What is this device known as

30) What are the measurements for which analog multimeter can be used without battery?