1. Which of the following falls under the category of plastic or non-fusion welding ? (a) Resistance welding. (b) Electron beam welding. (c) Electro-slag welding. (d) Arc welding. 2. Which of the following falls under the category of fusion or non-pressure welding? (a) Resistance welding. (b) Metal-arc welding. (c) Ultrasonic welding. (d) Explosive welding. 3. […]
1. A perfect black body is one which (a) absorbs all incident radiations. (b) reflects all incident radiations. (c) transmits all incident radiations. (d) all of the above. 2. For the transmission of heat from one body to another it is essential that (a) both bodies are solids. (b) the two bodies are at different
1. The basic elements of an electric drive are : (a) electric motor and the transmission system. (b) electric motor, the transmission and control system. (c) the transmission and control system. (d) electric motor and conversion equipment. 2. Electric drive is becoming more and more popular because (a) it is simple, clean, compact and reliable.
1. In ac distribution system the voltage can be controlled by using (a) tap changing transformer. (b) booster transformer (c) induction regulator. (d) any of the above. 2. Tap changing transformers are employed for (a) stepping down the voltage. (b) stepping up the voltage. (c) supplying low voltage current to instruments. (d) both stepping up
1. The frequency of carrier in the carrier current pilot scheme is in the range of (a) 1 kHz to 10 kHz. (b) 10 kHz to 25 kHz. (c) 25 kHz to 50 kHz. (d) 50 kHz to 500 kHz. 2. The frequency of carrier transmitted by microwave pilot is in the range of (a)
1. Purpose of backup protection is (a) to increase the speed. (b) to increase a reach. (c) to leave no blind spot. (d) to guard against failure of primary. 2. Protective relays are the devices that detect abnormal conditions in electrical circuits by measuring (a) voltage. (b) current. (c) constantly the electrical quantities which differ
1. Which of the following results in a symmetrical fault ? (a) Single-phase-to earth. (b) Phase-to-phase. (c) All the three phases-to earth. (d) Two phases-to earth. 2. Which portion of the transmission system is more prone to faults? (a) Alternator. (b) Transformer. (c) Overhead lines. (d) Underground cable. 3. Which portion of the power system
1. The capacitance of a cable depends upon the (a) length of the cable. (b) relative permittivity of dielectric used in cable. (c) ratio of sheath diameter and core diameter. (d) all of the above. 2. The charging current drawn by the cable (a) lags behind the voltage by 90°. (b) leads the voltage by
1. Bundled conductors are used to (a) reduce inductance of the line. (b) reduce both inductance and capacitance. (c) reduce corona loss. (d) reduce corona loss and the line inductance. 2. A 3-phase overhead transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to ‘d.’ If now the conductors of the
1. A 3 -phase, 4-wire system is commonly used for (a) primary distribution. (b) secondary distribution. (c) primary transmission. (d) secondary transmission. 2. The rated voltage of a 3-phase power system is given as (a) RMS phase voltage. (b) peak phase voltage. (c) RMS line to line voltage. (d) peak line to line voltage. 3.