The half-life of a radioactive sample is 3 days. After 9 days, fraction remaining is MCQ with Answer and Explanation

Explanation:
Joule's law states that heat produced H = I²Rt, where I is current, R resistance, t time. This quantifies electrical energy converted to thermal energy in resistors. Ohm's law relates V, I, R; Faraday's and Lenz's laws concern electromagnetic induction. Memory aid: 'Joule heating ∝ I²R'. This definition-based question tests knowledge of fundamental laws in electricity, commonly examined in competitive exams. Applications include electric heaters, fuses, and incandescent bulbs. Always distinguish Joule's law (heating) from power formulas (P=VI=I²R=V²/R).

Explanation:
Ohm's law V=IR is linear relationship, valid for ohmic materials like metals at constant temperature. Non-ohmic do not follow linear I-V. Semiconductors are non-ohmic.

Explanation:
V ∝ 1/r. So if r doubled, V halved = 5 V.