1. Army public school Gwalior
Name : Shikha Kumari
Class:12 -B
Adm. No. -16892
Submitted To : Mr . Upendra
Gupta
2. Acknowledgment
I would like to express my special thanks of
gratitude to “Mrs. UPENDRA GUPTA’’ Physics
teacher at “ARMY PUBLIC SCHOOL GWALIOR” for
their able guidance and support in completing
my project.I would also like to extend my
gratitude to the Principal Sir “Dr. Arvind Kumar
Sikarwar’’ and Vice Principal Ma’am“ Mrs. Vivian
Singh’’ for providing me with all the facility that
was required
3. Certificate
This is to certify that “Shikha Kumari" student of class
“XII B” of your school has successfully completed
their Chemistry Investigatory Project on topic
“Comparitive study of the rate of fermentation of
various food materials”under the guidance of “Mrs.
Mithlesh Chauhan’’.
---------------- ----------------
Mrs. Mithlesh Chauhan. Shikha
Kumari
4. IN D E X
• Introduction
• History
• Aim
• Material required
• Theory
• Procedure
• Diagram
• Result
• Precautions
• Bibliography
6. Solenoid
• The solenoid is an electromechanical device that
converts electrical energy to mechanical energy.
Solenoids are also known as electromagnets
because it generates the magnetic field from the
electric current flowing in the circuit.
• The magnetic property of the solenoid is not
permanent. It stays as long as the current flows
through the circuit.
7. HIS T O R Y
• Roughly 4,000 years ago, a Greek shepherd named
Magnes is said to have been tending his sheep in a
region of northern Greece called Magnesia. He took a
step and suddenly found that the nails that held his
shoe together and the metal tip of his staff were stuck
fast to the rock he was standing on! Intrigued, he began
digging and discovered the first recorded lodestone.
Lodestones were henceforth known as “magnetite,”
probably named after Magnes or Magnesia.
Bar Magnet
8. Solenoid
• The term solenoid was coined in 1823 by André-Marie
Ampère, a French physicist, mathematician and lay catholic
who was one of the founders of the science of classical
electromagnetism, which he referred to as "electrodynamics".
“Solen” in Greek means channel or pipe, which is why he
named it Solenoid. Ampère was an autodidact and professor
at the École polytechnique and Collège de France, as well as a
member of the French Academy of Sciences. The ampere, a SI
unit of electric current measurement, is named after him. The
Eiffel Tower also features his name among its 72 inscriptions.
9. Experiment
•Aim:To increase the effect of the force of attraction
between a solenoid and a bar magnet ,when the
current through the solenoid is changed.
• Material required: a solenoid having a large
number of turns wound on a cylindrical
former, a bar magnet ,Rheostat, one way key
,battery, physical balance ,weight box ,thread
,connecting wires and sand paper.
10. Theory-current carrying solenoid as
magnetic
• Consider a straight solenoid having n turns per unit length and wound on a cylindrical former as
shown in Fig. When current I is passed through the solenoid, the strength of the magnetic field at
a point well inside it ,is given by
• where is absolute permeability of the free space. For the direction of current shown in the figure,
N-pole is developed on the right face and S-pole is developed on the left face of the solenoid.
• From the equation it follows that the strength of the magnetic field produced and hence the
strength of the magnetic poles developed at the two faces of a solenoid is directly proportional to
1. The number of turns per unit length of the solenoid
2. The current passed through the solenoid.
11. To investigate the force of attraction
between a solenoid and a bar magnet
• The experimental arrangement shown in Fig.can be used to investigate the effect of
force of attraction between the solenoid and magnet, when the current through the
solenoid is changed.
• The bar magnet is suspended from the left arm of a physical balance. The weights are
added to the right pan, so as to counter balance the weight of the bar magnet. The
solenoid carrying current is placed vertically below the bar magnet. The current through
the solenoid is passed in such a direction that the magnetic pole developed on its upper
face is opposite to that of the lower end of the bar magnet. Due to the force of
attraction between the solenoid and the bar magnet, the beam of the physical balance
will remain no longer horizontal. The weights are added to the right pan, till the beam of
the balance again becomes horizontal. Thus, the additional weights placed on the right
pan gives the measure of the force of attraction between the bar magnet and the
solenoid. By moving the sliding contact of the rheostat, the current through the solenoid
is increased in steps and force at attraction between the solenoid and bar magnet is
measured by placing weights in the right pan. If the graph is plotted between current (1)
through the solenoid and force of attraction (F) between the bar magnet and the
solenoid, it will be a straight line as shown in Fig
12. Procedure
• 1. Remove the left pan of the physical balance and suspend the bar
magnet with its 5-poles pointing downwards from the hook.
• 2. Place the solenoid vertically below the bar magnet, so that the
solenoid and the bar magnet possess a common
• 3. Make the neat and tight connections as shown in Fig.For the
direction of current through the solenoid as shown in the figure, N-
pole will be developed on its upper face border to confirm it, pass
current through the solenoid for a while and see whether the solenoid
attracts the bar magnet or not. In case t repels reverse the terminals of
the battery.
• 4. Take out plug from the one-way key. Add weights to the right pan of
the balance, till the beam becomes horizontal The weights placed on
the pan will be equal to the weight of the bar magnet and the left pan
removed from the balance Let it be equal to m .
13. • 5. Move the sliding contact of the rheostat to the extreme left and insert
plug in the one-way key. Adjust the current through the solenoid, so that
there is a measurable force of attraction between the bar magnet and
the solenoid. The beam of the balance will tilt towards left. Add weights
on the right pan so that the beam again becomes horizontal Let M be the
total weights on the right pan and I be the current passing through the
solenoid. Then, force of attraction between the bar magnet and the
solenoid, when current I is passed through it, is given by
• F= (M-m)g,
• where g is acceleration due to gravity.
• 6. By moving the sliding contact of the rheostat, go on increasing the
current through the solenoid in steps and each time determine the force
of attraction between the bar magnet and the solenoid by noting the
additional weights placed on the pan
• 7. Record the observations in a tabular form.
• 8. Plot a graph between the current I (along X-axis) and force F (along Y-
axis). It will be a straight line as shown in fig .
15. Result
• As the graph (as shown in fig)between F and I is a
straight line the force of attraction between bar
magnet and solenoid increases linearly with
increase of current through the solenoid
16. Precautions
1. The Connection should be neat and clean
2. The direction of flow of current through the
solenoids should be such that the magnetic pole
developed on its upper and is opposite to the pool of
the magnet facing it.
3. Excess of bar magnet should coinside with the axis of
solenoid.
4. There should be no magnetic substances near the bar
magnet.
5. The connecting wires carrying the current should be
kept as far as possible from the bar magnet.
