Recent questions tagged over

Description : State any two advantages of MCB over Fuse. State the standard specifications of MCB available in the market.  

Last Answer : Following advantages of MCB over Fuse: 1. No need of replacement of fuse wire. 2. Manually restore of supply is simple. 3. Fault understanding by visual inspection 4. More safe than fuse The standard specifications of ... 6A, 10A,16A,20A, 25A, 30A, 32A, 40A, 50A, 60A and 63A 6. 250V and 450 v

Description : Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.

Last Answer : Parts Insulating Materials  Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils.  ... Transformer bushings Porcelain  Insulation between transmission line and pole. Porcelain

Description : State advantages of short pitch winding over full pitch winding in alternators. 

Last Answer : Advantages of Short Pitch Winding over Full Pitch Winding in Alternators: 1) Short pitching reduces the amount of copper needed for end connection when compared with full pitched coil. 2) They ... reduced, thereby increasing the efficiency. 4) The power quality of generated emf is improved. 

Description : What do you mean by active filter? State its advantages over passive filter . Define pass band & stop band with respect to filter.

Last Answer : Active Filter: Active Filter is formed by using active element along with the passive components.  Advantages of Active filter over Passive filter: High value of pass band gain can be obtained. It is ... pass band.  Stop Band Filter: The frequency range which is attenuated is known as stop band.

Description : State two advantages of digital system over analog system.

Last Answer : 1. They are less susceptible to noise. 2. The effect of fluctuation in the characteristic of the components, ageing of components etc. is very small in digital circuits. 3. Digital circuits have capability of memory which makes them suitable for computers. 4. More accurate.

Description : Thyristor can be protected from over voltages by using

Last Answer : Thyristor can be protected from over voltages by using Voltage clamping device

Description : The main advantage of AC over DC is:  (A) Conversion flexibility from one voltage level to other (B) AC can be easily converted into DC by using a rectifier (C) AC is easy to maintain & can be easily distributed at long distances (D) All of the above

Last Answer : Ac is easy to maintain and ac can be easily converted to dc by rectifier .There is no commutator for conversion in ac that's why ac machines are weight less and more efficiency.ac machines occupy less space than dc .

Description : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Last Answer : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Description : The surge impedance for over head line is taken as  (1) 10-20 ohms (2) 50-60 ohms (3) 100-200 ohms (4) 1000-2000 ohms

Last Answer : The surge impedance for over head line is taken as 100-200 ohms

Description : In the induction type directional over current relay, when a short-circuit occurs in the circuit (A) power flows in reverse direction (B) power flows in normal direction (C) directional power element does not operate (D) over current element is not energized

Last Answer : In the induction type directional over current relay, when a short-circuit occurs in the circuit power flows in reverse direction

Last Answer : In over compounded generator, full load terminal voltage is more than no load terminal voltage.

Last Answer : An over excited synchronous motor on noload is known as synchronous condenser.

Last Answer : Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.

Last Answer : The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.