physics ii labwork report

Experiment Report 1MEASUREMENT OF RESISTANCE, CAPACITANCE, INDUCTANCE AND RESONANT FREQUENCIES OF RLC USINGVerification of the instructorsName: Nguyễn Văn LộcStudent ID: 20206564Group: 0

HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY

SCHOOL OF ENGINEERING PHYSICS

PHYSICS II LABWORK REPORT

Instructor: NGO DUC QUAN

Name: NGUYEN VAN LOC

Student ID: 20206564

Group: 2

Ha Noi, 2022

Experiment Report 1 MEASUREMENT OF RESISTANCE, CAPACITANCE, INDUCTANCE AND RESONANT FREQUENCIES OF RLC USING

OSCILLOSCOPE

Verification of the instructors

Name: Nguyễn Văn Lộc

Student ID: 20206564

Group: 02

I. EXPERIMENT MOTIVATIONS

-Understand a typical circuit

-Learn how to use electrical equipment including oscilloscope and function generator

-Improving experimental skills

II.EXPERIMENT RESULTS.

4.Determination of Resonant Frequency:

4 Determination of Resonant Frequency:

We can see that:

The theoretical result of resonant frequency is approximately equal to the directly measured results We can see that the RLC circuit (with properly smallresistance) becomes a good approximation to an ideal LC circuit

Experimental Report 2 MEASUREMENT OF MAGNETIC FIELD

INSIDE A SOLENOID WITH FINITE LENGTH

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Name: Nguyễn Văn Lộc

as it increases The graph is symmetric around the point x=15 (cm).

Relationship between the magnetic field and the applied voltage

Comparison of experimental and theoretical magnetic field

Experimental Report 3 INDUCTOR AND FREE OSCILLATION IN RLC CIRCUIT

Verification of the instructors

Name: Nguyễn Văn Lộc

Student ID: 20206564

Group: 02

I EXPERIMENT MOTIVATIONS

- Understanding the current across an inductor-resistor and RLC circuit

- Calculating the energy of the oscillation RLC circuit

II EXPERIMENTAL RESULTS Part

1: Resistance and Inductance of the

coil a Without core

VS = 1 (V)

I0 = 0,17

(A)

Slope S = 745,188286The resistance of the coil

Coil inductance

Explain: After putting the core inside the coil, the coil’s inductance is

significantly increase (from 7,89 mH to 93,13 mH) This phenomenon occurred because the core has higher permeability than the air, so magnetic field can be transferred through the core easier, thus the coil inductance increase

Part 2: Free oscillation of the RLC circuit a Frequency

The current in RLC circuit

T = 0,0018 (s)

LW/O = 7,89×10 (H)-3

C = 10×10 (F)-6

The frequency based on the graph

The frequency based on theoretical calculation

Comparison

Δ� ����������� = | − �� �������| = |555,5 − 566,6| = 11.1(��

b Energy

The total energy in RLC circuit

Comment:

- After stopping the electric power, the energy of the circuit does not decrease

rapidly to zero, it reduces to zero over a short period of time

- The energy of oscillations of the coil and the capacitor are damped

oscillations The difference in phase of them is 180 degree

The energy of the circuit loses by the heat of the resistor at rate i R2

The graph of total energy is steepest at the time that the magnetic energy reaches a local maximum because in these times, the current through the coil

is highest, and the loss of energy is mainly due to the resistance of the coil (ΔQ=i R).2

Experimental Report 4 VERIFICATION OF FARADAY’S LAW OF ELETROMAGNETIC

INDUCTION

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North

North-South

North- North

South-South

2)150 turn coil

R = 0.4 (Ω); L = 1 (mH)Pole Voltage Peak 1 Voltage Peak 2

North-South

South-South

III/Comment and Explanation

Faraday’s Law of Electromagnetic Induction:

A voltage is induced in a circuit whenever relative motion exists between a conductor and a magnetic field and that the magnitude of this voltage is proportional to the rate of change of the flux

So, we have:

+)

Comparison between the first voltage peak and second voltage peak:

-The two voltage peak has opposite sign corresponding to the direction of the magnetic field line’s rate and direction of change According to Faraday’s Law, the induced electromotive force acts in the direction that opposes the change in magnetic flux

-Also, the magnitude of second voltage peak is greater than that of the first peak.This can be explained by the motion of the magnet bar When the magnet

is released to fall through the coil, its motion is free fall Therefore, the velocity

of the bottom pole when it falls through the coil is larger than that of the top pole This means the change in magnetic field increases in time, and according

to the Faraday’s Law above, this result in the greater magnitude of the second peak

+)

The shape of the graph

-Both graphs are approximately symmetric about the point when ΔΦ =0 �

(rate of change of the magnetic field flux equals zero) This can be explained by Faraday’s law, which states that the induced voltage through the wire induces a current that creates a magnetic flux in the direction opposing the change in flux, and the fact that the magnetic field line goingin/out the north and the south pole of the magnet are exactly the same.+)

Comparison between two coil

-The maximum voltage for the coil with more turns is higher than the one with fewer turn, because the magnitude of voltage is proportional to the number of turns in the coil, as shown in the equation:

Experimental Report 5

INVESTIGATION OF TRANSMISSION OF ELECTROMAGNETIC WAVE

(MICROWAVE)

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Name: Nguyễn Văn Lộc

II. Experimental Results

1.Investigation of straight-line propagation of microwaves

• Microwave propagates best in straight line

2.Investigation of penetration of microwaves

• When a dry absorption plate (electrical insulator) is put between transmitterand receiver, the volt-meter slightly decrease

Conclusion:

● Microwave can penetrate through the dry absorption plate

● Not all of the microwave will penetrate through the dry absorption plate, apart of them will be absorbed by the absorption plate

3.Investigation of screening and absorption of microwaves

Observation:

• When a reflection plate (electrical conductor) is put between transmitter andreceiver, the volt-meter shows a value that very small compared to the valuewhen the absorb plate is absent In this case, the volt-meter show a valueapproximate 0 (0.01)

Conclusion:

• Most of microwave will not go through the reflection plate

4.Investigation of reflection of microwaves Observation:

Reflector angle ( )o Incidence angle ( )o

• When the arrow is the bisector of 2 rails (the reflector angle is equal to theincidence angle), the volt-meter shows maximum value.

Conclusion:

• Microwave reflects best when perpendicular bisector of the reflection plate

is the bisector of an angle created by the transmitter and receiver

• When the microwave reflects, the angle of incidence equals the angle of

reflection 5 Investigation of refraction of microwaves

the value slightly increase Conclusion:

Microwaves has diffraction properties

7. Investigation of interference of microwaves

Observation:

• When the probe is moved parallel to the plate, the value on the volt meter isoscillating Number of maxima = 3

Conclusion: Microwave has property of interference.

8. Investigation of polarization of microwaves

When the grating is aligned at 45 , the value on the volt meter is higher thano

vertical case, but lower than horizontal case Conclusion:

• When we put a polarization grating between transmitter and receiver, themicrowave (electromagnetic) will be polarized as shown in fig 1

Because the vertical wave is electric wave, and the receiver’s signal we receiver is Voltage Therefore:

• With vertical polarization grating, only the vertical wave can go through.The receiver’s signal is big

• With horizontal polarization grating, only the horizontal wave can go through The receiver’s signal is very small (approximate to 0)

• With 45 inclined polarization grating, a part of vertical wave and horizontalwave can go through The receiver’s signal is smaller than when we usevertical polarization grating and bigger than when we use horizontalpolarization grating.

9. Determining wavelength of standing waves

Experiment Report 6 DETERMINATION OF SPECIFIC HEAT RATIO OF AIR

BASED ON CLEMENT DESORME’S METHOD

Verification of the instructors

Name: Nguyễn Văn Lộc

Student ID: 20206564

Group: 02

I. Experimental Motivation:

To determine the specific heat ratio � ��/�� = for air

II. Experimental Results:

1.Calculate figures for :�

2.Calculate the uncertain of :�

III Comparison and conclusion:

o Theoretically, we can calculate the specific heat ratio of air by using theformula

, where i = 5 which is the Degree of Freedom (DOF) of ideal gas (in this case it is air)

Hence, we get:

= 63.9 ±

ℎ 0.6 (��)

o The experiment result is a bit different from the theoretical result due toinstrumental uncertainty, observational uncertainty and environment uncertainty.