हिंदी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान कक्षा 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.

विकल्प

  • 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
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 19: Electric Current through Gases - MCQ [पृष्ठ ३५२]

APPEARS IN

एचसी वर्मा Concepts of Physics Vol. 2 [English] Class 11 and 12
अध्याय 19 Electric Current through Gases
MCQ | Q 5 | पृष्ठ ३५२

संबंधित प्रश्न

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


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


Let i0 be the thermionic current from a metal surface when the absolute temperature of the surface is T0. The temperature is slowly increased and the thermionic current is measured as a function of temperature. Which of the following plots may represent the variation in (i/i0) against (T/T0)?


The constant A in the Richardson−Dushman equation for tungsten is 60 × 104 A m−2K−2. The work function of tungsten is 4.5 eV. A tungsten cathode with a surface area 2.0 × 10−5 m2 is heated by a 24 W electric heater. In steady state, the heat radiated by the heater and the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan's Constant = 6 × 10−8 W m−2 K−1. Assume that the thermions take only a small fraction of the heat supplied.


Define the term "Threshold frequency", in the context of photoelectric emission.  


Answer the following question.
Define the term "Threshold frequency", in the context of photoelectric emission.


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


Why do metals have a large number of free electrons?


What do you mean by electron emission? Explain briefly various methods of electron emission.


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?


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


The work function of a metal is 2.31 eV. Photoelectric emission occurs when the light of frequency 6.4 × 1014 Hz is incident on the metal surface. Calculate

  1. the energy of the incident radiation,
  2. the maximum kinetic energy of the emitted electron and
  3. the stopping potential of the surface.

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×