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Dual Nature of Radiation and Matter
Previous year questions
2 min read
Dual Nature Of Radiation And Matter
- It's good to be already prepared. Go through the previous year questions
1
The concept of Photoelectric effect
Photons with energy
$5eV$
are incident on a cathode
$C$
in a photoelectric cell. The maximum energy of emitted photo electrons is
$2eV$
. When photons of energy
$6eV$
are incident. on
$C$
, no photoelectrons will reach the anode
$A$
, if the stopping potential of
$A$
relative to
$C$
is :
A
$−3V$
B
$+3V$
C
$+4V$
D
$−1V$
View solution
The photoelectric threshold wavelength of silver is
$3250×10_{−10}m$
. The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength
$2536×10_{−10}m$
is :
(Given
$h=4.14×10_{−15}eVs$
and
$c=3×10_{8}ms_{−1}$
)
A
$≈0.3×10_{6}ms_{−1}$
B
$≈6×10_{5}ms_{−1}$
C
$≈6×10_{6}ms_{−1}$
D
$≈61×10_{3}ms_{−1}$
View solution
Light of frequency
$1.5$
times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?
A
four times
B
one-fourth
C
zero
D
doubled
View solution
2
The concept of wave nature
An electron of mass
$m$
and a photon have same energy
$E$
. The ratio of de-Broglie wavelength associated with them is:
A
$c1 (2mE )_{21}$
B
$(2mE )_{21}$
C
$c(2mE)_{21}$
D
$c1 (E2m )_{21}$
(
$c$
being velocity of light)
View solution
An electron of mass m with an initial velocity
$V=V_{0}i^(V_{0}>0)$
enters an electric field
$E=−E_{0}i^$
(
$E_{0}=$
constant
$>0$
) at
$t=0$
. If
$λ_{0}$
is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is?
A
$λ_{0}(1+mV_{0}eE_{0} t)$
B
$λ_{0}t$
C
$(1+mV_{0}eE_{0} t)λ_{0} $
D
$λ_{0}$
View solution
An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is, (nearly) :
$(m_{e}=9×10_{−31}kg)$
A
$12.2×10_{−13}m$
B
$12.2×10_{−12}m$
C
$12.2×10_{−14}m$
D
$12.2nm$
View solution
An electron is accelerated from rest through a potential difference of
$V$
volt. If the de Broglie wavelength of the electron is
$1.227×10_{−2}nm$
, the potential difference is :
A
$10_{2}V$
B
$10_{3}V$
C
$10_{4}V$
D
$10V$
View solution
The de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature
$T$
(Kelvin) and mass
$m$
, is:
A
$mkT 2h $
B
$mkT h $
C
$3mkT h $
D
$3mkT 2h $
View solution