Magnetic effect of electric current of class 10th.All you need from this chapter is available here.convenient for studying this chapter of class 10 NCERT book.BEST FOR EXAMS!

3. The term ‘magnetic effect of electric current’
means that an electric current flowing in a
wire produces a magnetic field around it . A
iron, steel, nickel and cobalt. A bar magnet is a
Magnet is an object which attracts pieces of
long, rectangular bar of uniform cross-section
which attracts pieces of iron, steel, nickel and
cobalt.
INTRODUCTION :-

4. The region surrounding a magnet , in which the
force of magnet can be detected is said to have a
magnetic field.
 Magnetic field is a quantity that has both
magnitude and direction ; as such it is a vector
quantity.
 The term is used for two distinct but closely
related fields denoted by the symbols B and H,
which are measured in units of tesla and amp
per meter respectively in the SI.B is most
commonly defined in terms of the Lorentz force it
exerts on moving electric charges.

6. The curved lines along which the iron filings align
themselves or the path along which the freely pivoted
magnetic needle moves is called the field lines or
magnetic lines of force.
The direction of the field is taken to be the direction
in which a north pole of the compass needle moves
inside it.

7. 1. Magnetic field lines are closed curves.
2. Magnetic field lines appear to start from N-pole
and appear to end at the south pole.
(within the magnet , they run from S- pole to N-
north pole)
3. Magnetic field lines repel each other.
4. No two magnetic lines cut each other. ( If they
intersect , a compass needle placed at the
intersection has to point two different directions at
the same time which is impossible.)

8. Earth's magnetic field, also known as
the geomagnetic field, is the magnetic field
that extends from the Earth's interior to where
it meets the solar wind, a stream of charged
particles emanating from the Sun.
 Its magnitude at the Earth's surface ranges
from 25 to 65 microtesla (0.25 to 0.65 gauss).
It is approximately the field of a magnetic
dipole tilted at an angle of 10 degrees with
respect to Earth's rotational axis, as if there
were a bar magnet placed at that angle at the
center of the Earth.
Unlike a bar magnet, however, Earth's
magnetic field changes over time because it is
generated by a geodynamic (in Earth's case, the
motion of molten iron alloys in its outer core).

10. 1. A magnetic compass shows the presence
and direction of the magnetic field
around a straight length of current-
carrying wire.
2. The current through a wire produces a
magnetic field.
3. The shape of the magnetic field lines for
a straight conductor is concentric
circles.
4. These concentric circles become larger
as we move away from the wire.

11. •When you wrap your right hand
around the straight conductor such
that the thumb points in the direction of
the current, the fingers will wrap
around the conductor in the direction
of the field lines of the magnetic field..

13. 1. The magnetic field lines are near circular at the points where
the current enters or leaves the card board
2. Within the space enclosed by the coil, the field lines are in
same direction.
3. Near the centre of the coil, the magnetic lines are almost
parallel to each other. Thus mag. Field near the centre of
the coil may be considered uniform.
4. At the centre of the coil the plane of magnetic field lines is
at right angle to the plane of the coil.
5. If there is a circular coil having n turns, the field produced
is n times as large as that produced by a single turn ,as the
current in each turn has the same direction and the field
due to each turn add up.

15. o A coil of many circular
turns of insulated copper
wire wrapped closely in the
shape of a cylinder is called
a solenoid.
o A solenoid produces a
magnetic field when
electric current is passed
through it.
o The pattern of the magnetic
field lines around a current-
carrying solenoid is similar to
that of a bar magnet.
o One end of the solenoid is
like a magnetic north pole
while the other is like the
south pole
o

18.  The directions of the current, force, and
magnetic field can be illustrated through a
simple rule called Fleming’s left-hand rule, if
the direction of current is at right angles to
the direction of the magnetic field.
 According to this rule, stretch the thumb,
forefinger, and middle finger of your left
hand such that they are mutually
perpendicular.
 The first finger points in the direction of the
magnetic field and the second finger in the
direction of the current, then the thumb will
point in the direction of motion or the force
acting on the conductor.

19. The motion of a magnet with respect to
the coil produces an induced potential
difference, which sets up an induced
electric current in the circuit .This
phenomena is called electromagnetic
induction.
This was first studied by English
physicist Michael Faraday. In 1831,
Faraday made an important
breakthrough by discovering how a
moving magnet can be used to generate
electric currents.

20. Galvanometer
A galvanometer measures the
direction and relative strength
of an electric current from the
magnetic field it produces. The
pointer remains at zero (the
Centre of the scale) for zero
current flowing through it. It can
deflect either to the left or to
the right of the zero mark
depending on the direction of
current.

21.  Stretch the thumb, forefinger
and middle finger of right hand
so that they are perpendicular to
each other, as shown in the
figure. If the forefinger
indicates the direction of the
magnetic field and the thumb
shows the direction of motion of
conductor, then the middle finger
will show the direction of induced
current. This simple rule is called
Fleming’s right-hand rule.

22. In our homes, we receive supply of electric power through a
main supply, either supported through overhead electric
poles or by underground cables. One of the wires in this
supply, usually with red insulation cover, is called live wire.
Another wire, with black insulation, is called neutral wire. In
our country, the potential difference between the two is 220
V.
A fuse in a circuit prevents damage to the appliances and the
circuit due to overloading . overloading can occur when the
live and the neutral wire come in direct contact.
In such a situation, the current in the circuit abruptly
increases. This is called short-circuiting.