Under which condition, Transducers must operate?

The correct answer is option 4.

Solution:

In real-world applications, transducers encounter varying amounts of electromagnetic fields. So, the transducer should be able to operate under varying electromagnetic fields.

Additional Information

Need of Transducer

• It is quite difficult to determine the exact magnitude of the physical forces like temperature, pressure, etc.
• But if the physical force is converted into an electrical signal, then their value is easily measured with the help of the meter.
• The transducers convert the physical forces into an electrical signal which can easily be handled and transmitted for measurement. 

Difference Between a Transducer and a Sensor:

• A sensor is a device that measures a physical quantity.
• For example, in a mercury thermometer, the mercury simply expands when the temperature rises to give a reading for the user.
• Here there are no electrical inferences or changes.
• On the other hand, a transducer measures similar quantities as a sensor but the signal in a transducer is converted from one form to another.
• This is the reason why transducers are also referred to as energy converters.