0
Why the output voltage from a transformer is zero if a direct current flows through the primary coil?
Wiki User
∙ 12y ago
A transformer relies on AC current flowing through the primary to set up changing magnetic fields in the core. The field flows through the core and in to the secondary of the transformer, generating an AC current. The current must be AC, otherwise the magnetic field in the core of the transformer will saturate. In the same way, the armature of a dynamo or alternator must be moving in order to create a changing magnetic field to create current through the windings.
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
The incoming voltage from the current source to the transformer is called what?
The incoming voltage from the source to the transformer is called primary voltage.
Does a step-down transformer increase its voltage and and decrease it's current?
No. A step-down transformer's secondary voltage is lower than its primary voltage. The secondary current is determined by the load, and this causes a higher current in the primary winding.
What are the output voltage and current of a transformer determined by?
The secondary (output) voltage is determined by the primary voltage and the turns ratio of the transformer. The secondary current is determined by the secondary voltage and the load resistance.
A step-up transformer has 300 turns on the primary coil and 90000 turns on the secondary coil if the current flowing through the secondary is 5 amps what is the current flowing in the primary?
If a step-up transformer has 200 turns on the primary coil and 3000 turns on the secondary coil, with a primary coil voltage of 90 volts and current of 30 amps, then the turns ratio is 200:3000, so the secondary voltage is 1350 voltage and the available current is 2 amps. (This ignores losses through the transformer.)
Why should the secondary of a voltage transformer not be short circuited?
A voltage transformer takes a primary voltage and steps it down to a smaller secondary voltage. This type of transformer will attempt to keep the secondary voltage at a specific ratio of the primary voltage. If you short it, massive current flow in the secondary is required to do this. For a similar reason a CT should never be open circuited - because it attempts to push a specific ratio of primary current through the secondary. If you open circuit the secondary, it takes a massive voltage on the secondary to accomplish this.
The incoming voltage from the current source to the transformer is called what?
The incoming voltage from the source to the transformer is called primary voltage.
What is the incoming voltage from the current source to the transformer called?
the incoming voltage from the current source to the transformer is called primary voltage.....
Does a step-down transformer increase its voltage and and decrease it's current?
No. A step-down transformer's secondary voltage is lower than its primary voltage. The secondary current is determined by the load, and this causes a higher current in the primary winding.
What are the output voltage and current of a transformer determined by?
The secondary (output) voltage is determined by the primary voltage and the turns ratio of the transformer. The secondary current is determined by the secondary voltage and the load resistance.
A step-up transformer has 300 turns on the primary coil and 90000 turns on the secondary coil if the current flowing through the secondary is 5 amps what is the current flowing in the primary?
If a step-up transformer has 200 turns on the primary coil and 3000 turns on the secondary coil, with a primary coil voltage of 90 volts and current of 30 amps, then the turns ratio is 200:3000, so the secondary voltage is 1350 voltage and the available current is 2 amps. (This ignores losses through the transformer.)
Does a transformer increase amps?
The primary current is determined by the secondary current, not the other way around. For example, a step up transformer will step up the primary voltage in proportion to the turns ratio of the transformer. Any secondary current is then determined by the secondary voltage and the load, NOT by the primary current. The primary current is then determined by the secondary current in proportion to the reciprocal of the turns ratio.
Why should the secondary of a voltage transformer not be short circuited?
A voltage transformer takes a primary voltage and steps it down to a smaller secondary voltage. This type of transformer will attempt to keep the secondary voltage at a specific ratio of the primary voltage. If you short it, massive current flow in the secondary is required to do this. For a similar reason a CT should never be open circuited - because it attempts to push a specific ratio of primary current through the secondary. If you open circuit the secondary, it takes a massive voltage on the secondary to accomplish this.
A transformer has a primary volt of 240v and a secondary volt of 48v what is the turn ratio?
3
The incoming voltage from the current source to the transformer is called the voltag?
primary
How do you measure the power input and power output for the step-up transformer?
Power input to a transformer = (voltage across the primary winding) x (current through the primary)Power output = (voltage across the secondary winding) x (current through the secondary)It doesn't matter whether the transformer is used in step-up, step-down or simple isolation.
What is the function of the primary current when the secondary winding of the transformer is open?
When the secondary of a transformer is opened, there is no longer any load on the transformer. There will be some current flowing in the primary winding, which is needed to induce the voltage in the secondary. This primary current is referred to as the "no load" current, and is indicative of the core losses in the transformer.
How should I calculate this. A single phase transformer is rated at 99kVA The primary voltage is 6.6kV and the secondary voltage is 220V Assume no losses and calculate The full load primary current?
First find the ratio of the transformer. 6600/220 volts. Second find the secondary current, I = W/E, 99000/220. Third divide the secondary current by the transformer ratio. The answer will be the primary current. To check your answer (W (or VA) = V x A) multiply the primary current times the primary voltage and the secondary current times the secondary voltage and they should both equal the transformer's kVA.
