On a hot summer night the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally the Huygen's principle leads us to conclude that as it travels the light beam
On a hot summer night the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally the Huygen's principle leads us to conclude that as it travels the light beam
A
becomes narrower
B
goes horizontally without any deflection
C
bends downwards
D
bends upwards
Text Solution
Verified by Experts
Since air is comparatively lighter near the ground the wavefronts do not remain parallel any more. Separation between two consecutive wavefronts is greater near the ground than that at above. Since a ray light is always normal to the wavefront hence the light beam horizontal to the earth's surface always bends up wards.
The option D is correct.
The option D is correct.
|
Topper's Solved these Questions
LIGHT WAVE AND INTERFERENCE OF LIGHT
CHHAYA PUBLICATION|Exercise AIPMT|1 VideosLIGHT WAVE AND INTERFERENCE OF LIGHT
CHHAYA PUBLICATION|Exercise NEET|2 VideosLIGHT WAVE AND INTERFERENCE OF LIGHT
CHHAYA PUBLICATION|Exercise WBJEE|4 VideosKIRCHHOFF'S LAWS AND ELECTRICAL MEASUREMENT
CHHAYA PUBLICATION|Exercise CBSE SCANNER|16 VideosMagnetic Properties of Materials
CHHAYA PUBLICATION|Exercise CBSE SCANNER|11 Videos
Similar Questions
Explore conceptually related problems
A light beam is incident on a denser medium whose refractive index is 1.414 at an angle of incidence 45^(0) . Find the ratio of width of refracted beam in medium to the width of the incident beam in air.
A swimming pool is filled with water up to its brim. A swimmer observes a source of light just over the edge of the pool looking from a depth of 2 m in water and at a distance of 1.5 m from the vertical wall of the pool. The source of the light is placed at a height of 3 m from the ground and at a distance of 4 m from the edge of the pool. Find the refractive index of water in the swimming pool.
Knowledge Check
The french physicist Louis de Broglie in 1924 postulated that matter like radiation show a dual behaviour . He proposed the following relationship between the wavelength lamda of a material particle its linear momentum p and planck constant h lamda=h/p =h/(mv) The de broglie relation implies that the wavelength of a particle should decreases as its velocity increases . it also implies that for a given velocity heavier particles should have shorter wavelength than lighter particles. The waves associated with particles in motion are called matter waves or de broglie waves. These waves differ from the electromagnetic waves as they (i) have lower velocities (ii) have no electrical and magnetic fields and (iii) are not emitted by the particle under consideration . The experimental confirmation of the de-broglie relation was obtained when Davisson ans Germer in 1927 observed that a beam of electrons is diffracted by a nickel crystal . as diffraction a characteristics property of waves hence the beam of electron behaves as a wave, as proposed by de-broglie. de- Broglie wavelength of an electron travelling with speed equal to 1% of the speed of light
The french physicist Louis de Broglie in 1924 postulated that matter like radiation show a dual behaviour . He proposed the following relationship between the wavelength lamda of a material particle its linear momentum p and planck constant h lamda=h/p =h/(mv) The de broglie relation implies that the wavelength of a particle should decreases as its velocity increases . it also implies that for a given velocity heavier particles should have shorter wavelength than lighter particles. The waves associated with particles in motion are called matter waves or de broglie waves. These waves differ from the electromagnetic waves as they (i) have lower velocities (ii) have no electrical and magnetic fields and (iii) are not emitted by the particle under consideration . The experimental confirmation of the de-broglie relation was obtained when Davisson ans Germer in 1927 observed that a beam of electrons is diffracted by a nickel crystal . as diffraction a characteristics property of waves hence the beam of electron behaves as a wave, as proposed by de-broglie. de- Broglie wavelength of an electron travelling with speed equal to 1% of the speed of light
A
400 pm
B
120 pm
C
242 pm
D
375 pm
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(-13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . (i)What is the wavelength of the light incident on the atom to raise it to the fourth quantum level from ground state ?
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(-13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . (i)What is the wavelength of the light incident on the atom to raise it to the fourth quantum level from ground state ?
A
952 Å
B
975 Å
C
1027 Å
D
1219 Å
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . For what wavelength of incident radiation He^+ ion will be raised to fourth quantum state from ground state?
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . For what wavelength of incident radiation He^+ ion will be raised to fourth quantum state from ground state?
A
243.7 Å
B
487.5 Å
C
731.2 Å
D
975 Å
Similar Questions
Explore conceptually related problems
What happens to a ray of light when it travels from one medium to another having equal refractive index?
The refractive index of the material of a prism is sqrt(2) and the angle of the prism is 30^(@) . One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface ) if its angle of incidence on the prism is
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . (ii) Radiations of how many wavelengths are possible in case of the excited atom in the example I to come to ground state?
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(-13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . Energy of which quantum state of He^+ ion will be equal to the ground level energy of hydrogen ?
H, He^(+), Li^(2+) are examples of atoms or ions with one electron each . The energy of such atoms when in the n-th energy state (according to Bohr,s theory , n=1,2,3…. =principal quantum number ) is E_n =(-13.6 Z^2)/(n^2) eV (1 eV =1.6xx10^(-19)J) . For the ground state ,n=1 . in order to raise the atom from the ground state to n=f , the suitable incident light should have a wavelength given by lambda=(hc)/(E_f-E_1) . But the atom cannot stay permanently in the f-energy state, ultimately , it comes to the ground state by radiating the extra energy , E_f-E_1 as electromagnetic radiation . The electron of the atom comes from n=f to n=1 in one or more steps using the permitted energy levels . As a result there is a possibility of emission of radiation with more than one wavelength from the atom. Planck's constant =6.63 xx10^(-34)J*s and velocity of light c=3xx10^(8)m*s^(-1) . The wavelength of radiation emitted for the transition of the electron of He^+ ion from n=4 to n=2 is