The probability of spontaneous emission increases rapidly with the energy difference between the two states.

Related MCQs

• Which of the following Einstein’s coefficient represents spontaneous emission?
• A burning wood in the fireplace has a surface temperature of 450°C. Assume the emissivity to be 1 and find the radiant emission of energy per unit area.
• A small light bulb (25 W) inside a refrigerator is kept on and 50 W of energy from the outside seeps into the refrigerated space. How much of temperature difference to the ambient(at 20°C) must the refrigerator have in its heat exchanger having an area of 1 m2 and heat transfer coefficient of 15 W/Km2 to reject the leak of energy.
• What is the unit for the coefficient of stimulated emission?
•                                    is used when the optical emission results from the application of electric field.
• 5 kW/m2. Determine the wavelength of emission maximum
• A large heat exchanger transfers a total of 100 MW. Assume the wall separating steam and seawater is 4 mm of steel, conductivity 15 W/m K and that a maximum of 5°C difference between the two fluids is allowed. Find the required minimum area for the heat transfer.
• 16 W/m K, with a temperature difference between the two sides of 20°C.
• For destructive interference to take place, the path difference between the two waves should be:
•            converts mechanical energy into hydraulic energy.