Q.In the following table, every entry on the left column can match with any number of entries on the right side. Pick up all those and write respectively against A, B, C and D.
Name of the force | Type of the force
A. Force due to tension in a string | P. EM force
B. Normal force | Q. Reaction force
C. Frictional force | R. Conservative force
D. Resistive force offered by air or water for objects moving through it. | S. Non-conservative force

[!TLDR] A-Q,R (tension is EM and, being a string force, is a reaction to whatever pulls it); B-P,Q,R (normal force is EM, a reaction force, and conservative in the sense of not dissipating energy on ideal rigid contact); C-P,S (friction is EM and non-conservative); D-P,S (air/water resistance is EM and non-conservative). [!ANSWER] A: P,Q B: P,Q C: P,S D: P,S

Every one of these four named forces is fundamentally ELECTROMAGNETIC in origin (P applies to all four -- tension, normal force, friction, and fluid resistance all arise from intermolecular EM interactions). A (tension in a string) is also a REACTION force in the sense that it arises in response to a pulling force applied to the string -- Q applies. B (normal force) is likewise a REACTION force, arising in direct response to a body pressing on a surface -- Q applies; for an ideal rigid, frictionless contact, normal force does no work and does not dissipate energy, so it can be treated as behaving conservatively in that limited sense, though it is not typically classed as a conservative force with an associated potential-energy function the way gravity is -- the safest matching is A: P, Q and B: P, Q. C (frictional force) is a classic NON-CONSERVATIVE force (S applies), since the work done against friction is path-dependent and lost as heat; it is not simply a 'reaction force' in the same sense as tension/normal, since it opposes relative sliding rather than reacting to an applied pull/push alone. D (resistive force of air or water on a moving object) is likewise NON-CONSERVATIVE (S applies), being velocity-dependent and dissipative, converting kinetic energy to heat in the fluid. [!ANSWER] A: P, Q B: P, Q C: P, S D: P, S

For each named force, first confirm it is electromagnetic (P, true for all four here), then classify it separately as a reaction force (Q), a conservative force (R), or a non-conservative force (S) based on its physical behaviour.

Treating 'reaction force' and 'conservative force' as mutually exclusive categories, or forgetting that ALL four listed forces share the common EM origin (P) even though they differ in their reaction/conservative classification.