Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
What is the primary purpose of an electric fuse in a household circuit?
To reduce resistance in the circuit
To increase current flow
To regulate voltage supply
To prevent overloading and short circuits
To prevent overloading and short circuits
An electric fuse is a safety device used in household electrical circuits to protect appliances and wiring from damage caused by excessive current. It consists of a thin wire made of an alloy with a low melting point, such as lead and tin, which melts and breaks the circuit when the current exceeds a safe limit.
An electric fuse is a safety device used in household electrical circuits to protect appliances and wiring from damage caused by excessive current. It consists of a thin wire made of an alloy with a low melting point, such as lead and tin, which melts and breaks the circuit when the current exceeds a safe limit.
Think of an electric fuse as the circuit's sacrificial guardianтАФlike a weak link in a chain designed to snap first before the heavy load damages the expensive bridge.
FUSE: Fast Until Sudden Excess
H=I2Rt тАФ Joule's law of heating determining heat generated
P=V├ЧI тАФ Electrical power formula relating voltage and current
According to Joule's law of heating, the heat generated in a conductor is proportional to the square of the current (H=I2Rt). When a short circuit or overloading occurs, a massive surge of current flows through the circuit, causing the temperature of the fuse wire to rise rapidly above its melting point. The wire melts immediately, creating an open circuit that halts the flow of current and protects valuable appliances from burning out.
A fuse wire is connected in series with the live wire of the household circuit.
It is made of an alloy of lead and tin due to its low melting point and moderate resistivity.
During a short circuit, the live wire and neutral wire come in direct contact, causing a massive surge in current.
Overloading occurs when too many high-power electrical appliances are operated simultaneously.
Inexpensive and simple automatic protection device
Acts faster than many circuit breakers during severe short circuits
Prevents electrical fires and damage to expensive appliances
Needs manual replacement after it blows out
Inconvenient during frequent power trips if improperly rated
Household distribution boards
Automotive electrical systems
Individual electrical appliances like televisions and refrigerators
Standard domestic fuses are rated for currents such as 1A, 2A, 5A, 10A, and 15A depending on the appliance load.
Option A is incorrect because fuses do not significantly reduce circuit resistance during normal operation.
Option B is incorrect because increasing current flow is hazardous and causes overheating.
Option C is incorrect because voltage regulation is handled by transformers and stabilizers, not fuses.
D is correct тАФ To prevent overloading and short circuits by breaking the circuit when excessive current flows.
Remember that safety devices like fuses and MCBs (Miniature Circuit Breakers) must always be connected in the live wire in series so that they completely disconnect the power supply during a fault.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants