Electrical Engineering

Capacity to the equivalent of the battery is reduced - that is, you'll run out of charge quicker but the voltage delivered will still be the same.

I asked this very question to my professor in electronics 101 in college! He explained to me the load side of the transformer if not connected to any load is open. This is a great

resistance to completing the circuit. This is transferred to the primary side of the transformer as a great resistance thus no current flow.

because train has heavy mass & due to heavy mass inertia is also very high so more effort is required getting motion in train.

it is also known that any type of motor required more initial torque for come in speed.

I wouldn't t reccomend twice the voltage but dc motors can run at 150% rated voltage for up to a minute with no adverse effects. That being said it shouldn't be a regular practice and it will definately need to cool off under less load between bursts. Typical use of this application would be in an electric vehicle more like a bicycle or a go kart.

because of its losses i.e iron and copper losses.

since iron loss depends on voltage (v)and copper loss depends on current(i).

Since a short circuit is, essentially, a zero impedance connection between nodes, the current in a short circuit is limited only by the ability of the source.

In the case of an ideal voltage source connected to an ideal short circuit, you would have infinite amperes.

The "levitation" of the train above the track uses powerful electromagnets, which push and pull at slightly varying strengths from the equally magnetized track. As anyone who has experienced an MRI medical exam can attest, the clanging of magnets against their mounts can be very noisy.

High voltage testing is performed to confirm the integrity of a cable's insulation. It is always carried out after a new cable has been installed and terminated, or whenever a new joint is installed.

in case of inductor or capacitor power factor is always zero.as power factor is cosine of phase angle between voltage and current. in case of inductor and capacitor phase angle between voltage and current is 90 so it become zero so if given power factor is zero then it can be inductor or capacitor.

A current transformer doesn't 'measure current'. It merely reduces a large current flowing through its primary to a smaller current which can be read by an ammeter connected to its secondary. At the same time, it electrically isolates the secondary circuit from the primary circuit, which is essential if the primary circuit is part of a high-voltage system.

Use a megger or a insulation tester. Place one lead on any of the phases nd other lead the alternator boy. Observe the indicator. In megger it s good with infinity or it must be minimum 100M OHM, IF IT SHOWs 50 it could be coz of moisture in winding by heating the alternator the insulation resistance value may improve

Connect a VOM to one winding. Momentarily connect a battery to the other winding. When the battery makes contact, a pulse will occur on the other winding. If the pulse is positive, then the terminal connected to the plus lead is in phase with the lead connected to the battery.

A 400/230-V three-phase generator hase three line terminals, together with a neutral terminal. The line voltage (i.e. the voltage between any pair of line terminals) is 400 V, while the phase voltage (i.e. the voltage between any line terminal and the neutral terminal) is 230 V.

A suppressor regulates the voltage and makes the power constant in a case of a spike or surge . A protector simply detects the surge and turns the unit off. Suppressor is good for things like computers you don't want to keep turning on and off . Like computers in a dmv or office

But terms such as protector, arrestor, suppressor, regulator, limiter, and TVSS describe devices that can perform same or completely different functions. Regulated voltage may mean light bulbs dim or brighten by as much as 50%. Each device can be so different that numbers are required to say what it really does. Even a computer's power supply could be called a suppressor and protector since it does both functions within limits.

Most often TVSS, suppressor, arrestor, SPD, limiter, and protector are different words for the same item. Those terms are too subjective to say more without details such as numbers.

when the load increases the amount of vapor increases , so the pressure inside the evaporator increases and as we r in the wet region inside the evaporator the pressure and the temp. are proportional so the temp. too will increase

but we use some valves to fix this problem , for example thermostatic expansion valve

it helps add more m dot of the refrigerant so the amount of heat from the load will be distributed over a larger mass so the pressure inside the evaporator will remain the same

A Buchholz relay is situated in an inclined pipe between the transformer itself and its expansion tank. It (a) provides an alarm should there be an oil leak or if excessive gas accumulation within the relay and, (b) will disconnect the transformer in the event of a major oil loss or a surge within the oil (caused by a fault within the transformer).

When an induction motor is pushed over synchronous speed it will become a generator and will deliver power back to the utility.

It is most likely a bad neutral connection. Disconnect the solenoid from the circuit and apply the working voltage to it from an extension cord if it is 120 volts. If the solenoid doesn't chatter, the problem is in the control circuitry. Check the schematic to find out how the solenoid is connected in the circuit. If it is through a relay, look to the relay for the cause. To prevent relay or contactor chatter all that has to be done is to clean the armature pole faces. Debris on the magnetic pole faces prevents the armature and the stator from closing completely and you will hear 60 or 50 Hertz chatter.

No.

Depends on whither you count not having wheels as different.

Outer, upper shape is not different.

The kW rating of a transformer can be calculated by multiplying the kVA rating by the power factor. For example, if the power factor is 0.8, then the kW rating of a 100 kVA transformer would be 80 kW. You can also use the formula: kW = kVA x power factor.