When a piece of pure silicon is doped with aluminium, then
The conductivity of the doped silicon piece will remain the same
The doped silicon piece will become n-type
The doped silicon piece will become p-type
The resistivity of the doped silicon piece will increase
Lamberts law is related to
Reflection
Refraction
Interference
Illumination
The width of depletion layer of a P-N junction
Decreases with light doping
Increases with heavy doping
Is independent of applied voltage
Is increased under reverse bias
Which of the following waves cannot be polarised?
Radio
Ultra violet
Infrared
Ultrasonic
The Laser is a beam of radiations which are
Non-coherent and monochromatic
Coherent and monochromatic
Non-coherent and non-monochromatic
Coherent and non-monochromatic
In a bipolar junction transistor
All the three regions (the emitter, the base and the collector) have equal concentrations of impurity
The emitter has the least concentration of impurity
The collector has the least concentration of impurity
The base has the least concentration of impurity
Photosynthesis takes place faster in
Darkness
Red light
White light
Yellow light
The wave of theory of light is based on
The laws of reflection
The laws of refraction
The inverse square law
Huyghens' principle
The wave theory of light can explain
Comptom effect
Photoelectric effect
Black body spectrum
Interference of light
The impurity atoms with which silicon should be doped to make p-type semiconductors are
Phosphorus
Antimony
Boron
Germanium
Addition of suitable impurities into semiconductor, is called
Doping
Mixing
Forming
Diluting
Universal gates are
AND and OR
OR and NOT
NAND and NOR
AND and XOR
The light of distant stars is affected by
Interstellar Dust
The Earth's Atmosphere
Both A & B
None of these
Purpose of an optical filter is to
Reflect lights of different colours
Dispense light into component colours
Refract light of different colours
Transmit or absorb light of different colours
The redness in atmosphere at Sunrise and Sunset is due to :
Refraction of light
Reflection of light
Dispersion of light
Scattering of light
The complete form of 'IC' in electronics is
Internal circuit
Independent circuit
Integrated circuit
Inbuilt circuit
A metal semiconductor junction diode is called ________
Schottky diode
Photo diode
Tunnel diode
P-N Junction diode
Where is a transistor most likely to be found ?
Wrist watch
Fuse
Hearing aid
Fluorescent lamp
Solids which conduct electricity at higher temperature but not at lower temperature are called
Super-conductor
Metallic-conductor
Semi-conductor
Insulator
Which of the following is used for regulated electric supply ?
Zener diode
Junction diode
Gun diode
Tunnel diode
Which one among the following components is used as an amplifying device?
Transformer
Diode
Capacitor
Transistor
An integrated circuit is more advantages than a coventional circuit because
They make the electric equipments more reliable and easier for servicing
A faulty part of a conventional circuit may be difficult to locate and repair
If a part of the integrated circuit fails the entire circuit is simply replaced
All of these
Optic fibres are used in :
CAT scans
X-ray photos
Ultrasound scans
Endoscopy
When two semiconductors of p and n-type are brought in contact, they form p-n junction which acts like a/an
Conductor
Oscillator
Rectifier
Amplifier
The p wave of a normal Electrocardiogram indicates
Atrial depolarization
Ventricular repolarization
Atrial repolarization
Ventricular depolarization
When a strong beam of light is passed through a colloidal solution, the light will
Be scattered
Pass unchanged
Be absorbed
Be reflected
Golden view of sea shell is due to
Diffraction
Dispersion
Polarization
Reflection
For which Diode is used ?
Modulation
Oscillation
Amplification
Purification
What is a compound microscope?
A microscope that has one lens.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
A microscope whose lenses are concave.
A microscope whose lenses are convex.
What is colour of light related to ?
Amplitude
Frequency
Quality
Velocity
In electronics what comes under tank circuit ?
Resistance and capacity
Resistance and inductance
Capacity and inductance
Resistance, capacity and inductance
Fibre optics work on the principle of
Scattering of light
Total internal absorption
Total internal reflection
Optical rotation
Which of the following features of a tunnel diode is its drawback?
Extremely high frequency response
Very wide temperature range of operations
Instability due to negative resistance
Very low power consumptions
The material used in the fabrication of a transistor is
Aluminium
Copper
Silicon
Silver
In a Laser (say neon laser) all the atoms emit the light waves of
Same frequency
Same amplitude
Same phase
All of these
The scientist who first sent electromagnetic waves to distant places is
James Clerk Maxwell
Heinrich Hertz
Thomas Alva Edison
John Logie Baird
The formation of brilliant colors in a thin soap film is a consequence of the phenomena of
Polarization and interference
Diffraction and dispersion
Multiple refraction and dispersion
Multiple reflection and interference
Which of these waves can be polarized ?
Sound waves in air
Longitudinal waves on a string
Transverse waves on a string
Light waves
Which one among the following components can not be developed within an ''integrated circuit"?
Diode
Triode
Transformer
Transistor
The distance between node and adjacent antinode is 30 cm. The wavelength is
30 cm.
90 cm.
120 cm.
60 cm.
Parabolic mirrors are used in
Car headlights
Driving mirrors
Dentists mirros
Shaving mirros
The sky appears blue due to
Rayleigh scattering
Mie scattering
Back scattering
None of these
In quantum mechanics a particle is represented by a
Wave
Wave packet
Particle
None of these
What is the phenomenon which established the transverse nature of light ?
Reflection
Interference
Diffraction
Polarisation
Instrument for measuring blueness of the sky or ocean is called ________
Bathymeter
Ceraunograph
Cyanometer
Barometer
Which one of the following is used for sun glasses ?
Pyrex glass
Flint glass
Crooks glass
Crystal glass
For which one of the following, ''Diodes" are generally used for?
Rectification
Amplification
Modulation
Filtration
A soap bubble shows colours when illuminated with white light. This is due to
Diffraction
Polarisation
Interference
Reflection
Which of the following phenomenon helps to conclude that light is a transverse wave?
Interference
Diffraction
Polarisation
Refraction
A NOT gate can be implemented by:
A single diode
Two diodes
A single resistor
A single transistor