Question:
Aim: To study the pattern and direction of the magnetic field produced by the electric current that flows through different conductors.
Materials: Straight wire, coiled wire, thin cardboard, solenoid and iron filings
Apparatus: Compass, retort stand with clamp, power supply (D.C. 3 V), connecting wire and crocodile clip
Instruction
1. Set up the apparatus as shown in Figure 7.17.
2. Sprinkle some iron filings evenly on the white cardboard. Start the power supply and tap the cardboard gently until a magnetic field pattern is formed.
3. Stop the power supply and sketch the magnetic field pattern that has been formed.
4. Place four compasses around the straight wire as shown in Figure 7.18.
5. Restart the power supply and observe the direction of the needle of the compasses.
6. Stop the power supply. Mark the direction of the current flow and the direction of the magnetic field in the pattern you have drawn in step 3.
7. Reverse the direction of the current flow and observe the pattern and the direction of the magnetic field again.
8. Repeat steps 1 to 7 by replacing the straight wire with coiled wire and solenoid.
Questions
1. What is the purpose of using the iron filings and compass in this activity?
2. Are the magnetic field patterns for all three conductors similar?
3. What can you observe in the magnetic field when the direction of the electric current is reversed?
Answer:
1. Iron filings are used to show the magnetic field patterns and the compass is used to show the direction of the magnetic field.
2. Straight wire, coiled wire and solenoid produce different magnetic field patterns.
3. When the direction of the electric current flow is reversed, the direction of the magnetic field line is also reversed. However, the pattern of the magnetic field remains the same.
Aim: To study the pattern and direction of the magnetic field produced by the electric current that flows through different conductors.
Materials: Straight wire, coiled wire, thin cardboard, solenoid and iron filings
Apparatus: Compass, retort stand with clamp, power supply (D.C. 3 V), connecting wire and crocodile clip
Instruction
1. Set up the apparatus as shown in Figure 7.17.
2. Sprinkle some iron filings evenly on the white cardboard. Start the power supply and tap the cardboard gently until a magnetic field pattern is formed.
3. Stop the power supply and sketch the magnetic field pattern that has been formed.
4. Place four compasses around the straight wire as shown in Figure 7.18.
5. Restart the power supply and observe the direction of the needle of the compasses.
6. Stop the power supply. Mark the direction of the current flow and the direction of the magnetic field in the pattern you have drawn in step 3.
7. Reverse the direction of the current flow and observe the pattern and the direction of the magnetic field again.
8. Repeat steps 1 to 7 by replacing the straight wire with coiled wire and solenoid.
Questions
1. What is the purpose of using the iron filings and compass in this activity?
2. Are the magnetic field patterns for all three conductors similar?
3. What can you observe in the magnetic field when the direction of the electric current is reversed?
Answer:
1. Iron filings are used to show the magnetic field patterns and the compass is used to show the direction of the magnetic field.
2. Straight wire, coiled wire and solenoid produce different magnetic field patterns.
3. When the direction of the electric current flow is reversed, the direction of the magnetic field line is also reversed. However, the pattern of the magnetic field remains the same.