मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान इयत्ता ११

The Anode of a Thermionic Diode is Connected to the Negative Terminal of a Battery and the Cathode to Its Positive Terminal.

Advertisements
Advertisements

प्रश्न

The anode of a thermionic diode is connected to the negative terminal of a battery and the cathode to its positive terminal.

पर्याय

  • No appreciable current will pass through the diode.

  • A large current will pass through the diode from the anode to the cathode.

  • A large current will pass through the diode from the cathode to the anode.

  • The diode will be damaged.

MCQ
Advertisements

उत्तर

No appreciable current will pass through the diode.

 

If the anode is given a negative potential relative to the cathode, the electrons are pushed back to the cathode. Hence, no current will flow through the diode.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 41: Electric Current through Gases - MCQ [पृष्ठ ३५२]

APPEARS IN

एचसी वर्मा Concepts of Physics Volume 1 and 2 [English]
पाठ 41 Electric Current through Gases
MCQ | Q 5 | पृष्ठ ३५२

संबंधित प्रश्‍न

Find the (a) maximum frequency and (b) minimum wavelength of X-rays produced by 30 kV electrons.


The work function of caesium metal is 2.14 eV. When light of frequency 6 × 1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the

  1. maximum kinetic energy of the emitted electrons,
  2. Stopping potential, and
  3. maximum speed of the emitted photoelectrons?

How does one explain the emission of electrons from a photosensitive surface with the help of Einstein's photoelectric equation?


The work function of the following metals is given : Na 2.75 ev, K = 2.3 eV, Mo = 4.17 eV and Ni = 5.15 eV. Which of these metals will not cause photoelectric emission for radiation of wavelength 3300 Å from a laser source placed 1 m away from these metals? What happens if the laser source is brought nearer and placed 50 cm away?


Would you prefer a material with a high melting point or a low melting point to be used as a cathode in a diode?


Would you prefer a material with a high work-function or a low work-function to be used as a cathode in a diode?


Why does thermionic emission not take place in non-conductors?


The cathode of a diode valve is replaced by another cathode of double the surface area. Keeping the voltage and temperature conditions the same, will the place current decrease, increase or remain the same?


The wavelength λe of an electron and λp of a photon of same energy E are related by ______.


The wave associated with a moving particle of mass 3 × 10–6 g has the same wavelength as an electron moving with a velocity 6 × 106 ms–1. The velocity of the particle is


Emission of electrons by the absorption of heat energy is called ____________ emission.


Why do metals have a large number of free electrons?


Define the work function of a metal. Give its unit.


A 150 W lamp emits light of the mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.


In which case is electron emission from a metal not known?


Photoelectric emission is observed from a metallic surface for frequencies ν1 and ν2 of the incident light (ν1 > ν2). If the maximum value of kinetic energy of the photoelectrons emitted in the two cases are in the ration 1 : n then the threshold frequency of the metallic surface is ______.


Consider Figure for photoemission.

How would you reconcile with momentum conservation? Note light (photons) have momentum in a different direction than the emitted electrons.


Name the factors on which photoelectric emission from a surface depends.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×