0
Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
Work it out for yourself. The equation is: Z = E/I, where Z is the impedance, E is the supply voltage, and I is the load current.
The severity of an electrical shock is dependant upon what three things?
The severity of an electrical shock is dependent upon three things. Location or the proximity to the source. The second is amperage, the duration of the exposure and the pathway in the body. The third is the distance of the source.
What is horn gap of transformer?
Arcing horns (sometimes arc-horns) are projecting conductors used to protect insulatorson high voltage electric power transmission systems from damage during flashover. Overvoltages on transmission lines, due to atmospheric electricity, lightning strikes, or electrical faults, can cause arcsacross insulators (flashovers) that can damage them. The horns encourage the flashover to occur between themselves rather than across of the surface of the insulator they protect.[1] Horns are normally paired on either side of the insulator, one connected to the high voltage part and the other to ground. They are frequently to be seen on insulator strings on overhead lines, or protecting transformer bushings.
The horns can take various forms, such as simple cylindrical rods, circular guard rings, or contoured curves, sometimes known as 'stirrups'.
What is meant by 1.55 in busbar current calculation?
Busbar current rating for 1 square inch is 1000a.
Does current depends on its resistance?
The current flow in an electrical circuit depends on the applied electromotive force (EMF, measured in volts), and the total resistance along the entire circuit. Rising EMF or dropping resistance cause increased current flow
Why rotor slots is more than stator slots in induction motor?
rotor
slot
more.
it is
to
get
a
large
rotor
inductance value
of
inductance
the
stator
windings
What is current carrying capacity of 50 X 8 mm copper?
What is current carrying capacity of 50x8 mm copper flatbusbar.
How many rupees is electricity per unit?
Cost per unit of electricity depends the type of generation used. ie:- thermal hydel, nuclear etc. hydel electricity is cheaper and now a days it cost less than Rs.10 per unit in India. whereas thermal electricity cost less than Rs. 20 per unit
What the different between voltage generators and voltage transformers?
Generators generate and transformers step up or step down the voltage
Why there are no losses in DC transmission?
There are losses in d.c. transmission lines, due to their resistance. But there are no reactive losses. So, d.c. transmission lines have less losses in comparison to an equivalent a.c. transmission line.
Why line voltage at the secondary of transformer is above the required value?
ewan ko...................... ikaw ba alam mo
What is the function of exciter rotor and stator in Generator Operation?
In the operation of a standard generator, the exciter rotor and stator provide DC-type energy to an AC-type supply. This allows the exciter to maintain a constant DC source.
Why frequency of DC current is zero?
frequency if it will not zero then we cant tell its dc ...
AnswerFrequency is the number of alternations per unit time. As d.c. doesn't alternate, then zero divided by any quantity of time is zero!
A 'centre tap' refers to a connection midway along the length of a transformer winding. In North America, the 240-V secondary winding of a distribution transformer is centre tapped, and grounded, thus providing the neutral. Each outer terminal of that winding is then at a potential of 120 V with respect to the centre tap. This enables US and Canadian residences to have both 240 V and 120 V supplies. 240 V is then used for high power appliances, such as ranges (cookers), while 120 V is used to supply lower-power appliances, such as kettles, toaster, etc.
What should be the earth resistance of a good earth?
The lower the resistance you get in the grounding/earth system the better. In offshore a resistance from 1-2 ohm is a good earthing system. In Onshore a miximum of 10ohm is acceptable.
How calculate primary current in transformer the 50kva rating and 11kvprimary voltage?
The primary current is determined by the secondary current. So, if you don't know the secondary current, you cannot work out the primary current.
If the secondary isn't connected to the load, then the primary current is simply the primary voltage divided by the impedance of the primary winding.
You can, though, work out the 'rated' primary current (i.e. the value of current the primary can carry, continuously). For a single-phase transformer, this will be its rated apparent power (in volt amperes) divided by its rated primary voltage. So, in this particular case, we are looking at:
rated primary current = (50 x 103) / (11 x 103) = 4.55 A
How many ohms is a 1R5 resistor?
The answer is 1.5 ohms. The 'R' is a multiplier (x1), and its position is the decimal point. So 1R5 means 1.5. Similarly, 15R would mean 15 ohms, and R15 would mean 0.15 ohms. If the letter 'k' was used, then 1K5 would mean 1.5 kilohms If the letter 'M' was used, then 1M5 would represent 1.5 megohms, etc.
A definite time over-current relay operates like an instantaneous over-current relay coupled with a timer. Once current reaches the pick-up value, it initiates the timing circuit. As long as current stays above this pick-up value, the timer will continue to time. Once the definite time setting is reached, the relay gives trip signal to the circuit breaker.
What is the voltage tolerance of a standard electric motor?
the voltage tolerance of a standard electric motor is
When a load on a normally excited synchronous motor is increased its power factor tends to?
power factor normally goes to the lagging
What is the name of an instrument used to vary electrical resistance?
Rheostat is the name of an instrument used to vary electrical resistance.
