important practicle for class 12. please download it.

1. HALF WAVE RECTIFIER
CBSESUBMITTEDTO:
CENTRAL BOARD OF SECONDARY EDUCATION
DEHRADUN (UTTARAKHAND)
SUBMITTED TO:
SUBMITTED BY:
ABHISHEK KUMAR

2. A Project on
LIBRARY MANAGEMENT
Submitted for partial fulfilment of award of
Class 12
PHYSICS
By
S ABHISHEK KUMAR
Under the Supervision of
Er.

3. MAPLES ACADEMY
MEERUT ROAD, KHATAULI (MZN)
2019-2020
“HALF WAVE RECTIFIER”
This Project is Submitted in The Partial fulfilment of the
requirement for the award of the diploma of
CLASS 12
In
PHYSICS
STUDY CENTER
MAPLES ACADEMY
KHATAULI(MZN)
(Affliated to CBSE, DEHRADUN)
Submitted By:
ABHISHEK KUMAR

4. Submitted To:
CENTRAL BOARD OF SECONDARY EDUCATION
DEHRADUN (UTTARAKHAND
MAPLES ACADMY
KHATAULI(MZN)
PHYSICS INVESTIGATORY
PROJECT
MEASURING CURRENT
USING HALFWAVE
RECTIFIER
DONE BYNAME:-ABHISHEK KUMAR

5. CLASS:-XII-A
ROLL NO:-5
Index
Sl.No Content Page No
1
Acknowledgement
1
2 Introduction 2
3 Theory 4
4
Experiment
7
5
Observation Table
10
6 Result 11
7 Conclusion 12

6. 8 Bibliography 13

7. Acknowledgement
I would like to thank the Physics Lab Teacher
Mr.Chandra Shekhar sir for giving the
extraordinary idea about this project and
guiding this project until finish line.We would
also like to express our thanks to our Physics
Teacher Mr.Chandrashekhar sir for getting this
idea about this project and encouraging us.
Our thanks should not stop alone with
teachers.Our friends and parents even played a
big part in it.I see this project as a result of
hardwork from us and innovation from our
teacher.So, we once again thank all of them who
put their hands in it and made successful

8. INTRODUCTION
A rectifier a simple diode or group of diodes
which converts the Alternating Current (AC)
into Direct Current (DC).
We know that a diode allows electric current in
one direction and blocks electric current in
another direction. We are using this principle to
construct various types of rectifiers.
Rectifiers are classified into different types based
on the number of diodes used in the circuit or
arrangement of diodes in the circuit. The basic
types of rectifiers are: half wave rectifier and full
wave rectifier.
A half wave rectifier is a type of rectifier which
converts the positive half cycle (positive
current) of the input signal into pulsating DC
(Direct Current) output signal. The half wave
rectifier is the simplest form of the rectifier. We
use only a single diode to construct the half
wave rectifier.

9. The half wave rectifier is made up of an AC
source, transformer (step-down), diode, and
resistor (load). The diode is placed between the
transformer and resistor (load).
THEORY
The half-wave rectifier circuit is made by using a
semiconductor diode (D) with a load resistance
RL . The diode is connected in series with the
secondary of the transformer and the load

10. resistance RL. The primary of the transformer is
being connected to the ac supply mains.
The ac voltage across the secondary winding
changes polarities after every half cycle of input
wave. During the positive half-cycles of the input
ac voltage i.e. when upper end of the secondary
winding is positive w.r.t. its lower end, the diode
is forward biased and therefore conducts current.
If the forward resistance of the diode is assumed
to be zero (in practice, however, a small resistance
exists) the input voltage during the positive half-
cycles is directly applied to the load resistance RL,
making its upper end positive w.r.t. its lower end.
The waveforms of the output current and output
voltage are of the same shape as that of the input
ac voltage.
During the negative half cycles of the input ac
voltage i.e. when the lower end of the secondary
winding is positive w.r.t. its upper end, the diode
is reverse biased and so does not conduct. Thus
during the negative half cycles of the input ac
voltage, the current through and voltage across
the load remains zero. The reverse current, being

11. very small in magnitude, is neglected. Thus for
the negative half cycles no power is delivered to
the load.
Thus the output voltage (VL) developed across
load resistance RL is a series of positive half
cycles of alternating voltage, with intervening
very small constant negative voltage levels, It is
obvious from the figure that the output is not a
steady dc, but only a pulsating dc wave. To make
the output wave smooth and useful in a DC power
supply, we have to use a filter across the load.
Since only half-cycles of the input wave are used,
it is called a half wave rectifier.
Output of half wave rectifier is not a constant DC
voltage. In real life applications, we need a power
supply with smooth wave forms. In other words,
we desire a DC power supply with constant output
voltage. A constant output voltage from the DC
power supply is very important as it directly
impacts the reliability of the electronic device we
connect to the power supply.
We can make the output of half wave rectifier
smooth by using a filter (a capacitor filter or an

12. inductor filter) across the diode. In some cases an
resistor-capacitor coupled filter (RC) is also used.
EXPERIMENT
MEASUREMENT OF CURRENT USING
HALFWAVE RECTFIER

13. AIM:-
To determine the current by measuring
voltage and resistance using Halfwave Rectifier.
MATERIAL REQUIRED:-
• Diode
• Capacitor(50v)
• Voltmeter
• Resistance box
• Ac supply
• Wires for connection
PROCEDURE
i. Take a AC Supply and connect it to switch.
ii. Connect the terminal part of the AC to the p part
of the diode using wire.

14. iii. Now Connect the other part of the AC terminal
to the Capacitor.
iv. Connect the n-part of the diode to the capacitor.
v. Connect the both ends of a capacitor to the
resistance box.
vi. Place a connection between voltmeter and
resitance box by joining the terminals of
voltmeter. vii. Now power on theswitch and find
out the resultant voltage by changing the
resistance box.
viii. Calculate the current by measuring the mean
voltage and resistance using ohm’s law.
CIRCUIT DIAGRAM

15. OBSERVATION:-
RESISTANCE(in ohm) VOLT(in V)

16. 1 0.7
2 1.1
3 1.4
4 1.6
5 1.8
CALCULATIONS:-
Mean v=0.7+1.1+1.4+1.6+1.8 = 1.32 v
5
Mean R= 1+2+3+4+5 =3 ohm
5
Current I = Mean V / Mean R

17. = 1.32 / 3
= 0.264 Ampere.
RESULT:-
The average current produced by the halfwave
rectifier = 0.264 Ampere.
CONCLUSION
A half wave rectifier is rarely used in practice. It
is never preferred as the power supply of an audio
circuit because of the very high ripple factor. High
ripple factor will result in noises in input audio
signal, which in turn will affect audio quality.
Advantage of a half wave rectifier is only that its
cheap, simple and easy to construct. It is cheap

18. because of the low number of components
involved. Simple because of the straight
forwardness in circuit design.
Measuring the mean current flow helps us to
understand the amount of AC current passed
through the circuit.
BIBILOGRAPHY
• http://www.physics-and-
radioelectronics.com/electronic-devices-
andcircuits/rectifier/halfwaverectifier.htm
l
• http://www.electronicstutorials.ws/diode/
diode_5.html

19. • http://www.circuitstoday.com/half-
waverectifiers
• GOOGLE IMAGES
• www.wikipedia.com
• NCERT Physics book
• Comprehensive Lab Manual
PRECAUTIONS:-
DO NOT SWITCH ON THE CIRCUIT BEFORE
CHECKING WHEATHER IT IS CORRECT OR NOT
THE CONNECTION BETWEEN VOLTMETER
AND RESISTANCE BOX SHOULD BE MADE
CORRECTLY .
CONNECT ALL THE WIRES PROPERLY.
LOOSE
CONNECTION MAY END UP IN FAILURE OF
CIRCUIT.

20. CAPACITOR OF LESS VOLT MAY BE
CONNECTED TO THE DIODE.
SOURCES OF ERROR:-
o The p and n parts of the diode may be
changed. o The wire connection may be loose.