Flash Cards: Magnetic Effects of Electric Current
This chapter explores how electric currents create magnetic effects and their applications.
Magnetic Effects of Electric Current - Flash Cards
1/20
What is the magnetic effect of electric current?
1/20
Electric current flowing through a conductor generates a magnetic field around it.
How well did you know this?
2/20
Who discovered the relationship between electricity and magnetism?
2/20
Hans Christian Oersted discovered that electric current causes deflection in a compass needle in 1820.
How well did you know this?
3/20
Define magnetic field.
3/20
A magnetic field is the region around a magnet where magnetic forces can be detected.
How well did you know this?
4/20
What are magnetic field lines?
4/20
Magnetic field lines are the paths along which the north pole of a compass needle points, representing the magnetic field.
5/20
What does it mean if magnetic field lines are close together?
5/20
Close lines indicate a strong magnetic field, while spaced lines indicate a weaker field.
6/20
Describe the Right-Hand Thumb Rule.
6/20
If you hold a current-carrying conductor with your right hand, with your thumb pointing in the direction of the current, your fingers curl in the direction of the magnetic field.
7/20
What happens when the direction of current is reversed?
7/20
The direction of the magnetic field also reverses when the current direction is reversed.
8/20
What is an electromagnet?
8/20
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
9/20
Give an example of a practical application of electromagnets.
9/20
Electromagnets are used in electric bells, loudspeakers, and magnetic cranes for lifting heavy materials.
10/20
What is the formula for the magnetic field (B) around a long straight conductor?
10/20
B = (μ₀/4π) × (I/d), where I is the current and d is the distance from the conductor.
11/20
What is the unit of magnetic field strength?
11/20
The unit of magnetic field strength is the 'Tesla' (T), named after Nikola Tesla.
12/20
How do like and unlike poles behave?
12/20
Like poles repel each other and unlike poles attract each other.
13/20
What is a compass needle?
13/20
A compass needle is a small magnet that points towards the Earth's magnetic north.
14/20
How does increasing current affect the magnetic field strength?
14/20
Increased current strengthens the magnetic field produced around the conductor.
15/20
What is the effect of distance on the magnetic field strength?
15/20
The strength of the magnetic field decreases as the distance from the conductor increases.
16/20
What indicates a magnetic field direction?
16/20
The direction of the magnetic field is indicated by the direction in which a small compass needle points.
17/20
What happens to wires carrying current and placed parallel to each other?
17/20
Wires carrying current in the same direction attract each other, while those carrying current in opposite directions repel each other.
18/20
What are the two types of electromagnets?
18/20
The two types are temporary (created with electric current) and permanent (made of magnetized materials).
19/20
State the role of iron filings in demonstrating magnetic fields.
19/20
Iron filings align along magnetic field lines, visually demonstrating the shape and strength of the magnetic field.
20/20
Common mistake: Do magnetic field lines cross each other?
20/20
No, magnetic field lines never cross; if they did, it would imply a compass needle pointing in two directions simultaneously.
