Dual Nature of Radiation and Matter - Online Test
Q1. If an electron accelerated through a potential difference of 500 volt attains a speed of 1.33 then specific charge of the electron should be
Answer : Option B
Explaination / Solution:
eV0=12mv2em=v22V0=(1.33×107)22×500=1.76×1011CKg−1
Q2.
If an electron accelerated from rest through a potential of 200 V acquires a speed of 8.4, then its e/m is
Answer : Option B
Explaination / Solution:
eV0=12mv2em=v22V0=(8.4×106)22×200=1.76×1011CKg−1
Q3. If a potential of volts is applied across the electrodes of a CRT, then speed attained by the electrons is approximately (given: 1.76 C/kg)
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. Wavelength associated with a photon having energy 3.1eV is
Answer : Option A
Explaination / Solution:
λ(inA∘)=12375E(ineV)λ=123753.1≃4000A∘
Q5. If work function of a metal surface is 3.45 eV ,then maximum wavelength of a photon required to eject a photoelectron is
Answer : Option A
Explaination / Solution:
No Explaination.
Q6. Threshold frequency of a photon required to eject a photoelectron from the surface of cesium is
Answer : Option A
Explaination / Solution:
No Explaination.
Q7. If work function of a metal plate is negligible then the K.E.of the photoelectrons emitted when radiations of 1000 are incident on the metal surface is
Answer : Option A
Explaination / Solution:
No Explaination.
Q8. Maximum velocity of photoelectrons emitted from a metal surface having work function 4 eV is (given: frequency of incident radiations is Hz)
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. When ultraviolet light of wavelength 1000 is incident on molybdenum, then the maximum velocity of ejected electron (given: work function of molybdenum = 5.0eV) is
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. If threshold wavelength for tungsten is 2300 , then energy of the electrons emitted by UV light of wavelength 1800 is
Answer : Option B
Explaination / Solution:
No Explaination.
