Yeh calculator kisi bhi electrical wire ya cable ki electrical resistance (Ohmic value) nikalne ke kaam aata hai. Practical field me voltage drop calculate karne ke liye, cable sizing check karne ke liye, aur short circuit current analysis ke liye cable ki resistance pata hona sabse zaroori hai. Industrial standard ke hisaab se temperature badhne par resistance bhi badhti hai, isliye yeh calculator actual operating temperature par accurate value deta hai.

2. Input & Result Fields Explanation
   Design Standard (IEC/IS/NEC): Aap kis standard ke hisaab se calculation kar rahe hain. Standard badalne se reference temperature aur material ki base properties thodi change hoti hain.

Conductor Material: Copper (Cu) ya Aluminum (Al). Copper ki conductivity achi hoti hai toh resistance kam hoti hai. Aluminum thoda sasta aur halka hota hai par resistance zyada hoti hai.

Cable Length & Unit: Cable kitni lambi hai (Meters, Kilometers, ya Feet). Length jitni zyada hogi, resistance utni hi zyada hogi (Directly proportional).

Cross-Sectional Area (sq mm): Wire ki motai kitni hai. Area jitna bada hoga, current ko flow hone ke liye utni zyada jagah milegi, aur resistance utni kam hogi (Inversely proportional).

Operating Temperature (°C): Site par cable kis temperature par chalegi (normal ambient ya full load par 70°C/90°C). Garmi badhne se conductor ke electrons aapas me takrate hain, isliye resistance badh jati hai.

Final Result (Calculated Resistance): Yeh aapki final Ohmic value (Ohms me) hai jo aap directly apne voltage drop ya power loss (I^2 * R) ke formulas me use kar sakte hain.

1. Base Resistance Formula:
   R_base = rho * (L / A)

R_base: Resistance at standard temperature (20°C ya 25°C) in Ohms.

rho (ρ): Material ki resistivity (Ohm-meters me). Copper ke liye ~1.724 x 10^-8, Aluminum ke liye ~2.82 x 10^-8.

L: Cable ki length (Meters me).

A: Cross-sectional area (Square meters me). (Note: 1 sq mm = 10^-6 sq meters).

2. Temperature Correction Formula:
   R_final = R_base * [1 + alpha * (T2 – T1)]

R_final: Resistance aapke diye gaye operating temperature par.

alpha (α): Temperature coefficient (per °C).

T2: Operating temperature jo aapne enter kiya hai.

T1: Base temperature (Standard ke hisaab se 20°C ya 25°C).

exampleReal-World Example (Hinglish)
Maan lijiye site par ek Copper ki cable hai:

Length (L): 100 meters

Area (A): 2.5 sq mm

Operating Temp: 70°C

Step 1: Area ko standard meter me badlo.
A = 2.5 * 10^-6 = 0.0000025 sq meters

Step 2: Base resistance nikalo (IEC, 20°C). Cu ki rho = 1.724 * 10^-8.
R_base = (1.724 * 10^-8) * 100 / 0.0000025
R_base = 0.6896 Ohms

Step 3: 70°C par resistance nikalo (alpha = 0.00393).
R_final = 0.6896 * [1 + 0.00393 * (70 – 20)]
R_final = 0.6896 * [1 + 0.00393 * 50]
R_final = 0.6896 * [1 + 0.1965]
R_final = 0.6896 * 1.1965 = 0.8251 Ohms

(Yahi logic calculator fraction of a second me exact floating-point accuracy ke sath apply karta hai!)

Q1. Temperature badhne par resistance kyun badhti hai?
Ans: Jab conductor garm hota hai, toh uske andar ke atoms tezi se vibrate karne lagte hain. Is vibration ki wajah se electrons ka flow (current) takrata hai, jisse unhe rukaawat (resistance) ka samna karna padta hai. Isiliye heat badhne se resistance badh jati hai.

Q2. Copper aur Aluminum me kya best hai?
Ans: Technical point of view se Copper best hai kyunki iski resistance kam hoti hai aur same current ke liye kam mota wire lagta hai. Par practically badi lines (Transmission) me Aluminum use hota hai kyunki wo sasta aur halka hota hai.

Q3. Kya wire ki length double karne se resistance double ho jayegi?
Ans: Haan, bilkul. Formula R = rho * (L/A) ke anusaar, Resistance directly proportional hai length ke. Agar length double hogi, toh resistance bhi exactly double ho jayegi.

Q4. Area sq mm se sq meters me kyu convert kiya jata hai?
Ans: Kyunki formula me jo Resistivity (rho) ki unit hoti hai, wo “Ohm-meter” hoti hai. Calculation ko accurate rakhne ke liye sabhi units ka ek hi SI standard me hona zaroori hai (Meter aur Square Meter). Isiliye calculation ke waqt sq mm ko 10^-6 se multiply karke convert karte hain.