The acceleration due to gravity on Earth's surface is g. At a height equal to Earth's radius above the surface, g' will be: MCQ with Answer and Explanation

Explanation:
v = u - gt, at top v=0 => t = u/g = 30/10 = 3 s.

Explanation:
J. J. Thomson discovered the electron in 1897 through his experiments with cathode ray tubes. He demonstrated that cathode rays were actually streams of negatively charged subatomic particles, much smaller than atoms. Rutherford is famous for discovering the nucleus (gold foil experiment), Chadwick discovered the neutron, and Bohr developed the planetary model of the atom.

Explanation:
Magnetic field lines form concentric circles around a straight current-carrying wire, with direction given by right-hand thumb rule (thumb in current direction, fingers curl in field direction). This is derived from Biot-Savart law or Ampère's circuital law. Memory tip: 'Right-hand rule: thumb = current, fingers = field circles'. This fundamental field pattern is frequently tested in competitive exams. Always visualize field direction: for current toward you, field lines are counterclockwise. Distinguish from solenoid field (axial inside) or bar magnet (dipole pattern).