Explore topic-wise InterviewSolutions in .

The wavelength of light emitted by ATOMS is CHANGED by the application of as strong transverse electric FIELD to the source, the spectrum lines are split up into a number of sharply defined components. They are symmetrical about the position of the undisplaced line, and are proportional line, and are proportional to the field strength up to about 100,000 volts PER cm.

The wavelength of light emitted by atoms is changed by the application of as strong transverse electric field to the source, the spectrum lines are split up into a number of sharply defined components. They are symmetrical about the position of the undisplaced line, and are proportional line, and are proportional to the field strength up to about 100,000 volts per cm.

There is a change in the frequency of light radiation when the SOURCE or the OBSERVER move with RESPECT to ONE another. This phenomenon is KNOWN as doppler effect.

There is a change in the frequency of light radiation when the source or the observer move with respect to one another. This phenomenon is known as doppler effect.

In foggy weather scattering of light is large, becausse more scatters are PRESENT in the AIR. Wavelength of YELLOW light is large and intense yellow SOURCE are easy to produce. The yellow light will not undergo large scattering and will be observable from a LONG distance.

In foggy weather scattering of light is large, becausse more scatters are present in the air. Wavelength of yellow light is large and intense yellow source are easy to produce. The yellow light will not undergo large scattering and will be observable from a long distance.

1. LIGHT must go from a denser to RARE medium
2. The angle of incidence must be more than critical angle of incidence.

LET LIGHT be going from a denser to a RARER MEDIUM. If angle to incidence is greater than the critical angle of incidence no light is refracted into the medium. The WHOLE of light is reflected back into the first medium.

Let light be going from a denser to a rarer medium. If angle to incidence is greater than the critical angle of incidence no light is refracted into the medium. The whole of light is reflected back into the first medium.

52 0

52 0

INNER EDGES violet and outer edges is RED ( VIBGYOR )

Inner edges violet and outer edges is red ( VIBGYOR )

To have LARGER MAGNIFYING POWER.

To have larger magnifying power.

Because MAGNIFYING POWER is more when FOCAL LENGTH is SHORT.

Because magnifying power is more when focal length is short.

BACK of OBSERVER MUST be TOWARDS SUN.

Back of observer must be towards sun.

A CONTINUOUS EMISSION SPECTRUM.

A continuous emission spectrum.

Spectroscope is USED for only observing a spectrum. In a SPECTROGRAPH we can TAKE photograph of the spectrum. In the a spectrometer, there is ARRANGEMENT for making on measurements on the spectrum.

Spectroscope is used for only observing a spectrum. In a spectrograph we can take photograph of the spectrum. In the a spectrometer, there is arrangement for making on measurements on the spectrum.

A spectrum in which DIFFERENT colours overlap ONE ANOTHER.

A spectrum in which different colours overlap one another.

A SPECTRUM in which there is no OVERLAPPING of COLOURS.

A spectrum in which there is no overlapping of colours.

Apparent DEPTH of fish according to BIRD is less than the REAL depth.

Apparent depth of fish according to bird is less than the real depth.

Concave LENS, SINCE water is DENSER than AIR.

Concave lens, since water is denser than air.

FREQUENCY 

Frequency 

CONCAVE MIRROR

Concave mirror

CONCAVE MIRROR.

Concave mirror.

According to NEWTON PARTICLES are EMITTED by a source of light, and they travel in a straight line until the boundary of a NEW medium is encountered.

According to newton particles are emitted by a source of light, and they travel in a straight line until the boundary of a new medium is encountered.

LIGHT from a SODIUM lamp is YELLOW. A blue object absorbs yellow light falling on it from the lamp. THEREFORE object will appear black.

Light from a sodium lamp is yellow. A blue object absorbs yellow light falling on it from the lamp. Therefore object will appear black.

This is DUE to REFRACTION of LIGHT. 

This is due to refraction of light. 

The red CLOTH absorbs all light except red. THUS, when green light falls upon red cloth, it absorbs the greenlight and has nothing to REFLECT and thus, APPEARS BLACK.

The red cloth absorbs all light except red. Thus, when green light falls upon red cloth, it absorbs the greenlight and has nothing to reflect and thus, appears black.

The plane mirror is used as WORKING glass. The concave mirror is used for shaving as it gives MAGNIFIED image of the face. The Doctors also use it to see the FINE details of ear, nose, throat, etc. The convex mirror is used in automobiles. The mirror gives short images of the objects, thus enlarges the field of VIEW.

The plane mirror is used as working glass. The concave mirror is used for shaving as it gives magnified image of the face. The Doctors also use it to see the fine details of ear, nose, throat, etc. The convex mirror is used in automobiles. The mirror gives short images of the objects, thus enlarges the field of view.

This can HAPPEN when refractive indices of TWO are EQUAL. Under such conditions the lens MATERIAL does not reflect any light and is not visible.

This can happen when refractive indices of two are equal. Under such conditions the lens material does not reflect any light and is not visible.

Yes, the apparent depth increases, when water TANK VIEWED obliquely compared to the depth when seen near NORMALLY.

Yes, the apparent depth increases, when water tank viewed obliquely compared to the depth when seen near normally.

THOMAS YOUNG in 1801 

Thomas Young in 1801 

Both the surfaces of SUN glasses are curved but PARALLEL to each other. Therefore R 1 = R1

Both the surfaces of sun glasses are curved but parallel to each other. Therefore R 1 = R1

The ANGLE of REFRACTION s ZERO.

The angle of refraction s zero.

No change in the focal LENGTH of the CONCAVE MIRROR. It is half of its radius of curvature, no effect of external medium.

No change in the focal length of the concave mirror. It is half of its radius of curvature, no effect of external medium.

The FRONT surface of a glass ( thick ) is both REFLECTING and refracting. The origin of these IMAGES is MULTIPLE reflection of LIGHT with in the glass by the front and back surfaces.

The front surface of a glass ( thick ) is both reflecting and refracting. The origin of these images is multiple reflection of light with in the glass by the front and back surfaces.

A convex MIRROR, because it gives a VIRTUAL image SMALLER a size and hence WIDER view of TRAFFIC at the back. 

A convex mirror, because it gives a virtual image smaller a size and hence wider view of traffic at the back. 

Because a PARABOLIC mirror is free from spherical aberrations. So a source of light PLACED at the FOCUS of parabolic mirror produces a PARALLEL beam of light which easily visible even from a long DISTANCE.

Because a parabolic mirror is free from spherical aberrations. So a source of light placed at the focus of parabolic mirror produces a parallel beam of light which easily visible even from a long distance.

The REST of ENERGY is DISSIPATED as HEAT.

The rest of energy is dissipated as heat.

Two LIGHT sources which PRODUCES VISIBLE interfernce patterns with constant FORCE are KNOWN as coherent sources.

Two light sources which produces visible interfernce patterns with constant force are known as coherent sources.

Because, the efficiency of fluorescent TUBE is about 50 lumen / watt and whereas the efficiency of electric bulb is about 12 lumen / watt. Thus for the same amount of electric ENERGY consumed, the tube GIVES nearly four energy consumed, the tube gives nearly four times more light than the filament bulb.

Because, the efficiency of fluorescent tube is about 50 lumen / watt and whereas the efficiency of electric bulb is about 12 lumen / watt. Thus for the same amount of electric energy consumed, the tube gives nearly four energy consumed, the tube gives nearly four times more light than the filament bulb.

A white blotting PAPER. Because the SURFACE of white blotting paper is more diffusive than a PLANE mirror, hence, it scatters LIGHT in all directions. 

A white blotting paper. Because the surface of white blotting paper is more diffusive than a plane mirror, hence, it scatters light in all directions. 

It is the emission of LIGHT at low TEMPERATURE. Fluorescence and phosphorescence are examples.

It is the emission of light at low temperature. Fluorescence and phosphorescence are examples.

Shadows are formed because light RAYS TRAVEL in straight lines and cannot BEND around opaque objects in their PATH.

Shadows are formed because light rays travel in straight lines and cannot bend around opaque objects in their path.

Some CHEMICALS absorbs ultra violet LIGHT and that release energy as VISIBLE light. This is CALLED fluorescence.

Some chemicals absorbs ultra violet light and that release energy as visible light. This is called fluorescence.

They are USED in EYE surgery, SURVEYING, cutting steel etc.

They are used in eye surgery, surveying, cutting steel etc.

When light BENDS, it tricks US into seeing things in the wrong place. A mirage is caused by light REFLECTION in the ATMOSPHERE. 

When light bends, it tricks us into seeing things in the wrong place. A mirage is caused by light reflection in the atmosphere. 

Light travels in straight lines. But when it PASSES from one TRANSPARENT material to ANOTHER, the light RAYS BEND. This is called refraction.

Light travels in straight lines. But when it passes from one transparent material to another, the light rays bend. This is called refraction.

The OPTICAL TELESCOPES.

The optical telescopes.

The dutch PHYSICIST HENDRIK Lorentz used James Clerk Maxwell’s THEORY of electro - magnetic waves to explain how light is REFLECTED.

The dutch physicist Hendrik Lorentz used James Clerk Maxwell’s theory of electro - magnetic waves to explain how light is reflected.

LIGHT - EMITTING DIODES ( LED )

Light - emitting diodes ( LED )

500 0C 

500 0C 

THOMAS ALVA EDISON in 1879.

Thomas Alva Edison in 1879.

Frequency

Frequency

Olas ROMER.

Olas Romer.