A man pushes a wall but fails to move it. Work done is MCQ with Answer and Explanation

Explanation:
Wilhelm Roentgen discovered X-rays in 1895, won first Nobel in Physics.

Explanation:
For resistors in parallel, the reciprocal of the equivalent resistance (1/Rp) is the sum of the reciprocals of individual resistances. 1/Rp = 1/R1 + 1/R2 + 1/R3 = 1/2 + 1/3 + 1/6. Finding a common denominator (6): 1/Rp = 3/6 + 2/6 + 1/6 = 6/6 = 1. Therefore, Rp = 1 Ω.

Explanation:
According to Coulomb's Law, the electrostatic force (F) between two point charges is inversely proportional to the square of the distance (r) between them (F ∝ 1/r²). If the distance is doubled (r becomes 2r), the new force F' ∝ 1/(2r)² = 1/4r². Thus, the force becomes one-fourth of its original value.