Question

What does dielectric strength mean?

Answer 1

Hint: Generally we know that the dielectric is the poor conductor or insulator.
The valence electrons are tightly bound in dielectric here with no availability of loose electrons for conduction.
When the potential difference across the dielectric gets increased at some time the voltage becomes high enough to pull out the tightly bound electrons. Hence this voltage is called the dielectric strength.

Complete step by step Answer:
The insulating material can act as an insulator. The maximum electric field that it can do without undergoing dielectric breakdown and becoming electrically conductive is known as the dielectric strength of insulating material.
The dielectric strength also defines the maximum voltage that is required for the dielectric breakdown in an insulating material.
The potential difference is also called the breakdown voltage which is also called the dielectric strength. It refers to when the voltage exceeds the level of the dielectric strength then that particular dielectric will collapse and then the tightly bound electrons become loose and start to flow in the dielectric.
Here the Air is the very poor conductor of electricity. the air has the high dielectric strength
Finally, the dielectric strength is the maximum electric field that a pure material can withstand under ideal conditions without breaking down.

Note:
In many real-life appliances, dielectric strengths are found.
For example, Mica is one kind of insulator used in electric motor windings.
The liquid dielectric is known as the Naphtha which is used in the circuit breakers.