The magnetic field inside a long straight solenoid is MCQ with Answer and Explanation

Explanation:
Nucleus: protons (+) and neutrons (neutral); electrons orbit outside. Atomic number = proton count; mass number = protons + neutrons. Memory tip: 'Nucleus = nucleons (p+n); electrons in shells'. Basic atomic structure frequently tested in competitive modern physics sections.

Explanation:
Fuse uses heating effect (Joule heating I²R). When current exceeds limit, fuse wire melts due to heat, breaking circuit. Motor uses magnetic effect, generator uses electromagnetic induction, galvanometer detects current. Iron box, heater also use heating effect.

Explanation:
Work = 100×10×5=5000 J. Power = 5000/2 = 2500 W.