Physics - NLM Question with Solution | TestHub

The forces on the block are:

1. Weight Mg acting vertically downwards.

2. Normal reaction N acting perpendicular to the inclined surface (out of the plane).

3. Tension T acting horizontally to the right, as stated (the rope stays horizontal even when the block moves).

4. Friction acting along the plane, opposing the tendency of motion. The horizontal pull has a component T cos$\theta$ up the plane while Mg has a component Mg sin$\theta$ down the plane; friction acts along the incline to oppose the net tendency (up the plane when the block slides or tends to slide down).

$$\text{along plane: }\mathrm{Mg}\sin \theta \text{ down the plane},\mathrm{T}\cos \theta \text{ up the plane},{\mathrm{F}}_{\text{friction}}\text{ along the plane}$$

Only diagram (A) shows all four forces with these correct directions. Correct option: (A).