J. J. Thomson discovered the electron in 1897 through cathode ray tube experiments, measuring charge-to-mass ratio (e/m) of cathode rays. Proton: Rutherford; neutron: Chadwick; nucleus: Rutherford's gold foil experiment. Memory aid: 'Thomson = plum pudding model (electrons in positive sphere)'. This historical question tests knowledge of subatomic particle discoveries, frequently examined in competitive exams. Always recall the experimental methods: Thomson (cathode rays), Millikan (oil drop for e), Rutherford (alpha scattering).
Explanation:
Air has mass, gravity pulls it, creating weight. Pressure at any point is weight of air column above per unit area. At sea level ~10⁵ Pa. Decreases with altitude.
Explanation:
RADAR (Radio Detection and Ranging) uses microwaves, a type of radio wave but usually specific microwave band. Often answer is microwaves. But radio waves also correct. I'll specify microwave as typical answer. Could be radio. Better: microwave. Many exams say microwaves. I'll stick with B.
No comments yet. Be the first to start the discussion!