TNPSC Physics - Modern Physics
Exam Duration: 45 Mins Total Questions : 30
Consider the following statements
1.According to the de-Broglie hypothesis, particle have wave-like characteristics.
2.When an electron and proton have the same de-Broglie wavelength, they will have equal momentum.
Which of the statement(s) given above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
Neither 1 nor 2
In nuclear reaction, there is conservation of
- (a)
energy only
- (b)
momentum only
- (c)
mass, energy and momentum
- (d)
mass only
Rainbow is produced when sunlight falls on drops of rain.Which of the following physics phenomena are responsible for this?
1.Dispersion
2.Refraction
3.Internal reflection
Select the correct answer using the codes given below
- (a)
1 and 2
- (b)
2 and 3
- (c)
1 and 3
- (d)
All of these
The technique of collecting information about an object from a distance without making physics content with it is
- (a)
space shuttle
- (b)
remote control
- (c)
remote accessing
- (d)
remote sensing
Consider the following phenomena
1.Size of the Sun at dusk
2.Colour of the Sun at dawn.
3.Moon being visible at dawn
4.Polestar being visible in the sky.
Which of the above optical illusions?
- (a)
1,2 and 3
- (b)
3,4 and 5
- (c)
1,2 and 4
- (d)
2,3 and 5
Which of the following is used in oven?
- (a)
X-rays
- (b)
UV-rays
- (c)
Microwaves
- (d)
Radio waves
A radar beam consists of
- (a)
X-rays
- (b)
Ultraviolet rays
- (c)
infrared rays
- (d)
microwaves
Consider the following statements
1.A geostationary satellite is at an approximate height of 10,000 km.
2.FM transmission of music is a very good quality because the atmosphere or mass made noises which are generally frequency variation can do little harm.
Which of the following statement(s) is above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
Neither 1 nor 2
Penetrating power of X-rays does not depend on
- (a)
potential difference
- (b)
wavelengt
- (c)
energy
- (d)
current in the filament
It is possible to understand nuclear fission on the basics of the
- (a)
meason theory of the nuclear forces
- (b)
proton-proton cycle
- (c)
independent particle model of the nucleus
- (d)
liquid drop model of nucleus
The orbital velocity of an earth satellite near the surface of the earth is 7 km/s.If the radius of the orbit is 4 times the radius of earth,its orbital velocity would be
- (a)
3.5 km/s
- (b)
7 km/s
- (c)
7 km/s
- (d)
14 kms
In photoelectric effect, the number of photoelectrons emitted is proportional to
- (a)
velocity of incident beam
- (b)
work function of photo cathode
- (c)
frequency of incident beam
- (d)
intensity of incident beam
In a discharge tube, ionization of enclosed gas is produced due to collision between
- (a)
negative electron and neutral atoms/molecules
- (b)
photons and neutral atoms/molecules
- (c)
neutral gas atoms/molecule
- (d)
Positive ions and neutral atoms/molecules
With rise of temperature, the specific resistance of semiconductor
- (a)
decreases
- (b)
increases
- (c)
remains unchanged
- (d)
None of the above
A transistor is made of
- (a)
a metal piece sandwiched between two intrinsic semiconductors
- (b)
doped semiconductors
- (c)
intrinsic semiconductor
- (d)
None of the above
A pure semiconductor as
- (a)
a finite resistance which decreases with temperature
- (b)
a finite resistance which increases with temperature
- (c)
a finite resistance which does not depend upon temprature
- (d)
on finite resistance at 00C
The sky wave propagation is suitable for radio waves of frequency
- (a)
from 2Mhz to 20Mhz
- (b)
from 2 Mhz to 30Mhz
- (c)
from 2Mhz to 80Mhz
- (d)
up to 2 Mhz
The absorption of radio waves by the atmosphere depends on
- (a)
their frequency
- (b)
the polarisation of the wave
- (c)
their distance from the transmitter
- (d)
the polarisation of the atmosphere
In a p-type semiconductor
- (a)
electrons are the only carries
- (b)
holes are the only carries
- (c)
holes are the majority carriers and electrons are minority carries
- (d)
None of the above
The frequency band used for radar relay systems and television is
- (a)
VLF
- (b)
UHF
- (c)
VHF
- (d)
EHF
Through which mode of propagation the radio waves can be sent from one place to another
- (a)
space wave propagation
- (b)
sky wave propagation
- (c)
ground wave propagation
- (d)
All of the above
Modern communication system use
- (a)
digital circuits
- (b)
analog circuits
- (c)
combination of analog and digital circuits
- (d)
None of the above
Which of the following statement is correct
- (a)
Two isobar always have the same mass number
- (b)
Two isotopes always have the same mass number
- (c)
Two isotones always have same mass number
- (d)
Two isobars always have same atomic number
Consider the following statements
1.The size of atomic is of the order of 10-15 m.
2.The size of atomic nucleus is of the order of 10-15 m.
3.The electron emitted in beta radiation originates from decay of a neutron in a nucleus.
Which of the statements given above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
1 and 2
- (d)
1,2 and 3
In any fission process, the ratio mass of the fission products/mass of parent nucleus is
- (a)
equal to 1
- (b)
greater than 1
- (c)
less than 1
- (d)
depends on the mass of the parent nucleus
Resistivity of semiconductor depends on
- (a)
length of semiconductor
- (b)
shape of semiconductor
- (c)
atomic nature of semiconductor
- (d)
shape and atomic nature of semiconductor
Principle of Hydrogen Bomb is based on
- (a)
nuclear fission
- (b)
nuclear Radioactive disintegration
- (c)
Nuclear fusion
- (d)
either nuclear fission or nuclear fusion
Consider the statements
1.Photon is a particle of light.
2.Mass of photon is not defined.
3.Speed of photon is as the speed of light.
4.Photons are charged.
Which option is/are correct?
- (a)
1 and 2
- (b)
1,2,3 and 4
- (c)
1,2,3
- (d)
1 and 3
In an atomic explosion, release of large amount of energy is due to conversion of
- (a)
chemical energy into nuclear energy
- (b)
nuclear energy into heat
- (c)
mass into energy
- (d)
chemical energy into heat
If a U238 nucleus splits into two identical parts, the two nuclei so produced will be
- (a)
radioactive
- (b)
stable
- (c)
isotopes
- (d)
isobars