The wavelength of light in the visible region is about 550 nm (average wavelength) for yellow-green colour. Three materials with work functions are given as Al (4.28 eV), Cu (4.65 eV) and Na (2.75 eV). From which of these photosensitive materials, can you build a photoelectric device that operates with visible light?
(4) None of the above
What is the de Broglie wavelength associated with an electron, accelerated through a potential difference of 100 volts?
1. 0.123 nm
2. 0.232 nm
3. 0.031 nm
4. 0.312 nm
A particle is moving three times as fast as an electron. The ratio of the de Broglie wavelength of the particle to that of the electron is . The particle’s mass is:
An electron, an α-particle, and a proton have the same kinetic energy. Which of these particles has the shortest de Broglie wavelength?
4. All have the same de Broglie wavelength
The de Broglie wavelength associated with a ball of mass 150 g travelling at a speed of 30.0 m/s is:
What is the de-Broglie wavelength associated with an electron moving at a speed of
1. 0.244 nm
2. 0.135 nm
3. 0.157 nm
4. 0.111 nm
The wavelength of light in the visible region is about 390 nm for violet colour. The energy of photons in (eV) is:
1. 1.64 eV
2. 2.26 eV
3. 3.19 eV
4. 4.03 eV
The work function of caesium is 2.14 eV. The wavelength of incident light if the photocurrent is brought to zero by a stopping potential of 0.60 V will be:
1. 454 nm
2. 440 nm
3. 333 nm
4. 350 nm
The work function of caesium is 2.14 eV. The threshold frequency for caesium is:
Monochromatic light of frequency is produced by a laser. The power emitted is How many photons per second, on average, are emitted by the source?