The primary coil of a transformer is connected to a standard wall socket. A resistance R is connected across the secondary coil. The resistance across the secondary coil is increased. What happens to the current in the primary coil, and what happens to the power being supplied by the wall socket? Explain your answer.
Answer choices:
A) The current in the primary coil increases, and the power being supplied by the wall socket decreases
B) The current in the primary coil increases, and the power being supplied by the wall socket increases
C) The current in the primary coil decreases, and the ower being supplied by the wall socket decreases
D) The current in the primary coil decreases, but the power being supplied by the wall socket remains the same
E) The current in the primary coil decreases, and the power being supplied by the wall socket increases
When the resistance across the secondary coil of a transformer is increased, it affects the primary coil and the power being supplied by the wall socket.
To understand what happens, we need to consider the relationship between voltage, current, and resistance in a transformer. The voltage across the primary coil of a transformer is directly proportional to the voltage across the secondary coil, while the current in the primary coil is inversely proportional to the current in the secondary coil (as per the transformer equation).
Now, when the resistance across the secondary coil is increased, the current in the secondary coil decreases (Ohm's Law: V = I x R). Since the current in the secondary coil decreases, the current in the primary coil (inversely proportional) also decreases. This means that the current in the primary coil decreases.
The power being supplied by the wall socket is given by P = V x I, where P is power, V is voltage, and I is current. As the current in the primary coil decreases, the power being supplied by the wall socket decreases.
Therefore, the correct answer is:
C) The current in the primary coil decreases, and the power being supplied by the wall socket decreases.
To determine what happens to the current in the primary coil and the power being supplied by the wall socket when the resistance across the secondary coil is increased, we need to review the principles of transformers and the relationship between voltage, current, and power.
In a transformer, the primary coil is connected to the input voltage source (in this case, the standard wall socket), and the secondary coil is connected to the load (in this case, the resistance R). The transformer operates based on the principle of electromagnetic induction, where a changing magnetic field induces a voltage in the secondary coil.
When the resistance across the secondary coil is increased, it means the load connected to the secondary coil is becoming more difficult to push current through. This increased resistance in the secondary coil affects the current flowing through the entire transformer circuit.
According to Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R), when the resistance increases, the current decreases if the voltage remains constant. In this case, the voltage supplied by the wall socket is assumed to remain constant.
Therefore, by increasing the resistance across the secondary coil, the current in the primary coil decreases. This means that fewer electrons flow through the primary coil, resulting in a lower current.
Regarding the power being supplied by the wall socket, power (P) is calculated using the equation P = IV, where I is the current and V is the voltage. Since the voltage remains constant, and the current decreases due to the increased resistance across the secondary coil, the overall power supplied by the wall socket decreases. Therefore, the correct answer is:
C) The current in the primary coil decreases, and the power being supplied by the wall socket decreases.