Advertisements
Advertisements
प्रश्न
Name a metal that is used as an electron emitter. Give one reason for using this metal.
Advertisements
उत्तर
Thoriated tungsten (tungsten coated with carbon and thorium) is used as an electron emitter. Thoriated tungsten is used since it has a work function of only 2-6 eV and it needs to be heated to only 2000K to emit electrons.
संबंधित प्रश्न
Which particles are responsible for current in conductors?
1 calorie = _________ joule.
Why is an electric light bulb not filled with air? Explain why argon or nitrogen is filled in an electric bulb.
A bulb marked 12 V, 24 W operated on a 12 volt battery for 20 minutes. Calculate:
(i) the current flowing through it, and
(ii) the energy consumed
A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V.
calculate:
(i) the resistance of the wire and
(ii) the heat energy produced in 1 minute.
Two resistors A and B of 4 Ω and 6 Ω respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate the power supplied by the battery.
What would happen and why, to an electric bulb when it is connected across a supply of voltage (i) lower (ii) higher than its proper rating?
What is the order of current drawn by appliances connected to the ‘light circuit’ of a household?
State other bigger units of electric power and express them in watt.
In the given figure, the emf of the cell is 2.2 V, and if internal resistance is 0.6 Ω. Calculate the power dissipated in the whole circuit.
