The document discusses the electromagnetic spectrum. It defines key terms like wavelength and frequency. The electromagnetic spectrum includes all types of electromagnetic radiation organized based on their wavelength and frequency. Radiation is produced through the interaction of electric and magnetic fields and can be classified as luminous or nonluminous. Laws governing radiation include reflection, refraction, absorption, transmission, penetration, and scattering. Specific laws of radiation discussed are the Arndt-Schultz principle, the law of Grotthus-Draper, the cosine law, and the inverse square law. The document also briefly mentions uses of electromagnetic radiation but does not provide details.

1. ELECTRO
MAGNETIC
SPECTRUM
K E E R T H I P R I YA , M P T N E U R O,
A S S I S TA N T P R O F E S S O R

2. CONTENTS
INTRODUCTION
PRODUCTION
LAWS GOVERNING RADIATION
DIFFERENT LAWS OF RADIATION
USES

3. INTRODUCTION
WAVE LENGTH:
The
distance between two crests
or toughs of a wave

4. FREQUENCY:
Number of complete waves passed through a fixed point in a given
period of time.
VELOCITY:
The speed with which a wave can travel.
VELOCITY= WAVE LENGTH X FREQUENCY

5. Definition:
Electro magnetic spectrum is defined as range of all electro magnetic
radiations of varying frequency and wave length.
Based on emission, transmission, absorption and also on their properties.
Radiation is energy that travels and spreads as it goes.

6. PRODUCTION
Electro magnetic waves are propagated by interaction of electric and magnetic field.
Classification Of Electromagnetic Spectrum:
1. Luminous
2. Nonluminous

8. LAWS GOVERNING RADIATION
1. REFLECTION
2. REFRACTION
3. ABSORPTION
4. PENETRATION
5. SCATTERING

9. REFLECTION:
Change in direction of wave when it strikes different medium or surface.

10. REFRACTION:
Change in direction of wave when it passes from one medium to another
medium.

11. ABSORPTION :
The energy which stimulates cell to perform its normal function.
TRANSMISSION:
Propagation of waves through a biological surface to deeper tissue.
PENETRATION:
The distance travelled by the transmitted waves.
SCATTERING:
Change in direction of wave over a non homogenous structure

13. LAWS OF RADIATION
ARNDT-SCHULTZ PRINCIPLE:
No reactions or changes can occur in the body if the
amount of energy absorbed is not sufficient to stimulate the absorbing tissues.
LAW OF GROTTHUS-DRAPER:
Energy not absorbed by the tissues must be
transmitted.

14. COSINE LAW:
Optimal radiation occurs when the source of radiation is at right angles
to the center of the area being radiated.
INVERSE SQUARE LAW:
The intensity of radiation striking a particular surface varies inversely
with the square of the distance from the radiating source.
INTENSITY∞1/DISTANCE

15. USES

16. REFERENCES
ELECTROTHERAPY EXPLAINED BY LOW & REED
CLAYTON’S ELECTROTHERAPY
THERAPEUTIC MODALITIES FOR SPORTS MEDICINE AND ATHLETIC TRAINING BY W I
L L I A M .
THERAPEUTIC MODALITIES BY CHAD