Question bank — Electric charge — properties, quantization, conservation

False — ek negatively charged body mein protons se zyada electrons hote hain; sirf positive body mein kam hote hain. "Charged" ka sirf matlab hai counts match nahi karte, kisi bhi taraf.

True — additivity ka matlab hai $(+q)+(-q)=0$, jahan $q$ sirf shared magnitude hai. Poora system neutral hai, chahe har piece charged ho.

False — sirf isolated system ka total fixed hota hai. Individual objects freely charge swap karte hain (yahi toh touching conductors karte hain — figure 2 dekho).

False — tum sirf whole electrons move kar sakte ho, isliye transferred charge hamesha $ne$ hoti hai jahan $n$ ek integer hai. Aadha electron koi cheez nahi hai jo tum de sako.

False — ye glass se silk mein electrons transfer karke existing charge ko separate karta hai. Glass positive ho jaata hai, silk negative; kuch bhi create nahi hota (dekho Methods of Charging).

False — usme equal amounts ki positive aur negative charge hoti hai jo total mein cancel ho jaati hai. "Neutral" ka matlab balanced hai, empty nahi.

False — quarks confined hote hain aur kabhi akele observe nahi hote. Koi bhi free, isolatable particle $e$ ka integer multiple carry karta hai, isliye free-charge brick $e$ hi rehti hai.

False — charge ek signed scalar hai; force apna direction wahan se leta hai jahan charges geometrically baithe hain, charge se nahi (dekho Coulomb's Law).

Vacuum ke liye False — charge balance karta hai ($0\to (-e)+(+e)$), lekin energy aur momentum dono tab tak conserve nahi ho sakte jab tak koi nearby nucleus recoil absorb na kare. Iske liye matter ka present hona zaroori hai (figure 1).

Protons nuclei mein lock hote hain aur ordinary processes mein move nahi karte. Tum rod ko positive banate ho electrons remove karke, jo protons pehle se wahan hain unhe expose karke.

Kuch destroy nahi hua. Total pehle $+8\text{C}$ tha aur baad mein bhi $+8\text{C}$ hai ($+4$ each); sharing redistribute karta hai, delete nahi.

Induction object ki apni charge ko rearrange karta hai (ya uska kuch hissa ground kar deta hai); bina contact ke gap ke across koi charge nahi koodta. Isolated setup ka total phir bhi conserved rehta hai.

$4.8\times 10^{-19}/1.6\times 10^{-19}=3$, $2.5$ nahi — toh ye actually $3e$ hai aur bilkul allowed hai. Ek genuinely non-integer quantization se forbidden hota, lekin ye toh integer hai.

Ye energy aur momentum ke saath ek fundamental Conservation Laws in Physics result ke roop mein khadha hai, ek gehri symmetry se juda — koi ek-baar ki electrical convenience nahi.

Charge Earth mein flow ho jaati hai, jo ek bahut bada reservoir hai; ye relocate hoti hai, destroy nahi. Earth-plus-conductor ka total unchanged rehta hai.

Ek type sirf attract kar sakti thi (jaise gravity mein mass). Do signs isliye zaroori hain taaki like charges repel karein aur unlike charges attract karein, jo experiment se match karta hai.

Brick $e\approx 1.6\times 10^{-19}\text{C}$ itni chhoti hai ki $1\text{C}$ charge $\sim 6.24\times 10^{18}$ electrons hai; $n$ aur $n+1$ ke beech ka step smooth lagta hai, jaise door se sand fluid lagta hai.

Charge ka magnitude aur ek $\pm$ sign hota hai lekin koi direction nahi, isliye ye ek scalar hai. $+2\text{C}$ aur $-2\text{C}$ milake $0$ dete hain, $4$ nahi.

Ek akela photon jo do particles mein convert ho, wo energy aur momentum dono simultaneously conserve nahi kar sakta; ek massive teesra body recoil momentum absorb karta hai taaki dono satisfy ho sakein, jabki charge zero pe balanced rehta hai.

Kisi bhi conductor ke liye jo charge wo hold karta hai wo hai $q=CV$, toh uska potential hai $V=q/C$, jahan $C$ (uski capacitance) sirf size aur shape pe depend karta hai. Identical spheres ka identical $C$ hota hai; contact pe unhe ek common $V$ reach karna hota hai, aur $q=CV$ mein equal $C$ aur equal $V$ ke saath equal $q$ force hota hai — isliye total aadha-aadha split hota hai.

Haan — ek neutral system separated $+$ aur $-$ regions (ek dipole) hold kar sakta hai jinke parts ek doosre ko push aur pull karte hain; net charge zero, internal forces nonzero.

Haan — $q=0\cdot e=0$ yahi toh $n=0$ case hai. Quantization zero ko allow karta hai; neutral sirf wo integer multiple hai jisme $n=0$ hai.

Charge law se khud koi practical limit nahi hai, lekin aakhirkar field itna strong ho jaata hai ki charge ko wapas kheeche (sparking/breakdown), isliye ek real ball physically cap out ho jaati hai, isliye nahi ki $q=ne$ ise forbid karta hai.

Nahi — total $+5e$ hai, aur $+5e/2=+2.5e$ ek integer multiple of $e$ nahi hai. Practice mein ek real conductor billions of bricks hold karta hai, isliye sharing kabhi bhi zyada se zyada ek whole electron se off hoti hai: do spheres $+3e$ aur $+2e$ (ya ulta) pe settle hote hain, aur wo ek leftover brick ek sphere pe baithta hai — ek difference jo macroscopic scales pe measure karna bahut mushkil hai.

Haan — ek neutron ($0$) ek proton ($+e$), ek electron ($-e$), aur ek antineutrino ($0$) mein decay karta hai; pehle aur baad ki total charge $0$ hai. Bookkeeping exactly balance hoti hai (dekho Atomic Structure).