An X-ray tube operating at 50kV converts 1% energy in the form of X-ray. If the amount of heat produced is 495 watts, then the number of electrons colliding with the target per second is . Find the value of α.
Number of electrons colliding with the target per second is :
The correct answer is: 6.25
In a hydrogen atom following the Bohr’s postulates the product of linear momentum and angular momentum is proportional to (n) is the orbit number. Then ‘x’ is.
Linear momentum ⇒
Angular momentum ⇒
∴ Product of linear momentum and angular momentum ∝ n0.
The correct answer is: 0
Work function for aluminum metal is 4.125 eV. For photo electric effect from aluminum metal, the cut off wavelength (in nm) will be.
The correct answer is: 300
If the short wavelength limit of the continuous spectrum coming out of a coolidge tube is 10Å, then the de-Broglie wavelength (in Å)of the electrons reaching the largest metal in the coolidge tube is approximately.
The correct answer is: 0.3
Yellow light of 557 nm wavelength is incident on a cesium surface. It is found that no photo-electron flow in the circuit when the cathode anode voltage drops below 0.25V. Then the threshold wavelength (in nm) for photoelectric effect from cesium is.
The correct answer is: 625
Light of wavelength 5000Å falls on a sensitive plate with photoelectric work function of 1.9 eV. The kinetic energy (in eV) of the emitted photo-electron will be.
The correct answer is: 0.58
The ratio of de-Broglie wavelength of a proton and an α-particle accelerated through the same potential difference is.
The correct answer is: 2.828
When light of intensity 1 W/m2 and wavelength 5 × 10–7 m is incident on a surface, it is completely absorbed by the surface. If 100 photons emit one electron and area of the surface is 1 cm2, then the photoelectric current (in µA) will be.
Number of photon/second
Number of photon electron emitted/second by 1 photon = N/100
Photo electric current
The correct answer is: 0.4
The wavelength of Ln line in X-rays spectrum of 78Pt is 1.32 Å. The wavelength of Ln line in X-rays spectrum of another unknown element is 4.17Å. If screening constant for La line is 7.4, then atomic number of the unknown element is :
The correct answer is: 47
The intensity of an X-ray beam reduces to 36.8% of its initial intensity after traversing a gold film of thickness 5 × 10–3 m. Its absorption coefficient (in m–1) is :
The correct answer is: 200