Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
Specially designed PPE for electrical work includes _____ insulating gloves, matting, blankets, and covers.
Plastic
Rubber
Steel
Wood
Rubber
Quick Summary: Rubber is the preferred material for electrical PPE because it possesses high dielectric strength and excellent insulating properties, which prevent electric current from flowing through the worker to the ground. Specially engineered rubber items such as gloves, mats, and blankets provide a physical barrier against contact with energized conductors.
Rubber is the preferred material for electrical PPE because it possesses high dielectric strength and excellent insulating properties, which prevent electric current from flowing through the worker to the ground. Specially engineered rubber items such as gloves, mats, and blankets provide a physical barrier against contact with energized conductors.
I=RV — Ohm's law showing how high resistance minimizes current
Ed=dVbreakdown — Dielectric strength defining the voltage capacity of the insulator
The insulating property of a material is defined by its ability to resist the flow of electrons, measured by its dielectric strength (expressed in mmV). Rubber acts as a high-resistance barrier (R→∞) that maintains the potential difference across the protective layer, thereby reducing the leakage current (I=RV) through the human body to a negligible level.
Rubber PPE is categorized into classes (00 to 4) based on the maximum voltage they can safely withstand.
ASTM D120 is the standard specification for rubber insulating gloves.
Electrical PPE must be inspected for physical damage, punctures, or ozone checking before every use.
Matting provides step-potential protection in switchgear rooms.
Extremely high electrical resistivity
Flexibility allows for comfortable movement during work
Durability in harsh industrial environments
Susceptible to degradation from UV, oil, and extreme heat
Requires periodic electrical testing and re-certification
Can be punctured by sharp objects
Live-line maintenance on distribution circuits
Working in substation switchgear rooms
Operating disconnect switches and circuit breakers
Class 00 gloves are rated for 500V AC usage, while Class 4 gloves are rated for up to 36,000V AC.
Option A (Plastic) is generally not suitable for high-voltage PPE as it lacks the specific elastic dielectric properties required for safety standards.
Options C (Steel) and D (Wood) are conductive or semi-conductive, respectively, and are dangerous if used as insulators.
B is correct — Rubber is the industry-standard material for electrical insulating equipment due to its high dielectric strength and ability to prevent electric shock by blocking current paths.
Remember that voltage ratings for rubber gloves are based on the proof-test voltage, which is significantly higher than the maximum use voltage to provide a built-in factor of safety.