The magnetic field strength of a solenoid can be increased by inserting:
a wooden piece into it.
an iron piece into it.
a glass piece into it.
paper roll into it.
(2)
When a piece of soft iron is inserted inside a solenoid, then the strength of the magnetic field increases because the iron gets magnetized due to magnetic induction. This combination of the solenoid and the soft iron core so formed is called an electromagnet.
The magnetic field inside the solenoid is:
non-uniform
variable
same at all points
zero
(3)
The magnetic field inside the solenoid is same at all points. This is because the magnetic field lines inside the solenoid are in the form of parallel straight lines, which indicates that the magnetic field is uniform at all points inside the solenoid.
The magnetic field lines inside a solenoid are in the form of:
Curved line
Circular lines
Zig-zag lines
Parallel straight lines
(4)
The field lines inside the solenoid are in the form of parallel straight lines. This indicates that magnetic field is same at all points inside the solenoid.
Which of the following correctly describes the magnetic field near a long straight wire?
The field consists of straight lines perpendicular to the wire
The field consists of straight lines parallel to the wire.
The field consists of radial lines originating from the wire.
The field consists of concentric circles centred on the wire.
(4)
The magnetic field near a long straight wire consists of concentric circles whose centres lie on the wire. This can be confirmed by the Right-hand Thumb Rule.
According to this rule, if we put the thumb of our right hand in the direction of the current flow through the conductor/straight wire and encircle the wire with our fingers, then the direction of those fingers will correspond to the direction of the magnetic field.
Thus, the magnetic field lines will be in concentric circles around the conductor.
Inside the magnet, the field lines move:
from South to North
from North to South
away from North pole
away from South poles
(1)
Magnetic field is a vector quantity with both direction and magnitude. The direction of the magnetic field is taken as the direction in which a North pole of the compass needle moves inside it. The field lines emerge from the North pole and merge at the South pole, but inside the magnet, the direction of field lines is opposite, i.e., from South to North
An electron moves with a speed v along positive direction of the x-axis. If a magnetic field B acts along the positive y-direction, then the force on the electron will act along:
x-axis
y-axis
−vez-direction
+vey-direction
(3)
As the electron is moving in positive x-direction, according to Maxwell's right-hand thumb rule, the current is moving in negative x-direction and the magnetic field acts along positive y-direction.
By applying Fleming's left-hand rule, the thumb will be in negative z-direction, which is the direction of force.
The force exerted on a current carrying wire placed in a magnetic field is zero when the angle between wire and the direction of magnetic field is:
(4)
The force exerted on a current carrying wire placed in a magnetic field is zero when the angle between wire and the direction of magnetic field is
A force is experienced by the current carrying wire in the presence of an external magnetic field. This can be expressed as:
Where,
L is the length of the wire, I is the current, and is the angle between the current and the magnetic field.
We know that Therefore, the force exerted on a current carrying wire that is placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is
In the figure shown below, the point A and B are respectively:
North pole, South pole
South pole, North pole
North pole, North pole
South pole, South pole
(2)
As magnetic lines of force start from the North pole and terminate at the South pole.
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the North pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was:
Moving towards the solenoid
Moving into the solenoid
At rest inside the solenoid
Moving out of the solenoid
(4)
As due to electromagnetic induction.
The magnetic field of the current was discovered by:
Maxwell
Fleming
Oersted
Faraday
(3)
Hans Christian Oersted discovered that a compass needle got deflected when electric current passed through a metallic wire placed nearby.
