NEETPhysicsElectromagnetic WavesMCQ+4 / −1
The condition under which a microwave oven heats up a food item containing water molecules most efficiently is
- AMicrowaves are heat waves, so always produce heating.
- BInfra-red waves produce heating in a microwave oven.
- CThe frequency of the microwaves must match the resonant frequency of the water molecules.
- DThe frequency of the microwaves has no relation with natural frequency of water molecules.
View written solutionFree
Correct answer: C
The natural frequency of vibration of the water molecules in the food item should be same as that of the frequency of microwaves.
More from Electromagnetic Waves
- The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagatting in vacuum is equal to2012 · MCQ
- The electric field associated with an em wave in vacuum is given by E = 40 cos (kz 6 108 t) where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is2012 · MCQ
- The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by2011 · MCQ
- The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is2011 · MCQ
- The electric field of an electromagnetic wave in free space is given by where t and x are in seconds and metres respectively. It can be inferred that (1) the wavelength …2010 · MCQ
- Which of the following statement is false for the properties of electromagnetic waves ?2010 · MCQ
- The electric field part of an electromagnetic wave in a medium is represented by Ex = 0; …2009 · MCQ
- The velocity of electromagnetic radiation in a medium of permittivity 0 and permeability 0 is given by2008 · MCQ