By the end of this section, you will be able to:
- Explain why power plants transmit electricity at high voltages and low currents and how they do this
- Develop relationships among current, voltage, and the number of windings in step-up and step-down transformers
Think about what you already know about power dissipation, resistance, and heat loss to answer this question:
|To minimize heat losses for power transported across the country, it is best that current in the wires is…|
When the switch S is closed, the potential difference across R is:
|The primary coil of a transformer is connected to a battery, a resistor, and a switch. The secondary coil is connected to an ammeter.|
When the switch is thrown closed, the ammeter shows:
|An ideal transformer is shown below. The voltage on the primary circuit is 10V. The primary circuit has 4 turns, the secondary circuit has 8 turns.|
What is the voltage on the secondary circuit?
|An ideal transformer is shown below. The current in the primary circuit is 10 mA. The primary circuit has 4 turns, the secondary circuit has 8 turns.|
What is the current in the secondary circuit.
|An ideal transformer (no power loss) is shown below. The primary circuit has 4 turns, the secondary circuit has 8 turns.|
What is the ratio of the power dissipated in the primary circuit and the power dissipated in the secondary circuit?