In the equation F = ma, if mass is doubled and acceleration is halved, force becomes MCQ with Answer and Explanation

Explanation:
Convex mirror provides wider field and erect image, so R explains A correctly.

Explanation:
Electric potential V at a point is defined as work done per unit charge to bring a test charge from infinity to that point: V = W/q. Thus potential difference between two points is work per unit charge to move between them. Electric field intensity is force per unit charge; potential energy is work to assemble charges; capacitance is charge storage ability. Memory tip: 'Potential = work per unit charge; field = force per unit charge'. This definition-based question tests electrostatics fundamentals, frequently appearing in competitive exams. Always distinguish potential (scalar, work/charge) from field (vector, force/charge).

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).