| 1. | \(k_1x-k_2x=ma \) |
| 2. | \(\dfrac{k_1k_2}{k_1+k_2}x=ma \) |
| 3. | \(k_1x+k_2x=ma \) |
| 4. | \(\dfrac{k_1k_2}{k_1-k_2}=ma \) |
| (P) | \(f_A,~f_B>0\) | (Q) | \(f_A,~f_B<0\) |
| (R) | \(f_A>0,~ f_B<0\) | (S) | \(f_A<0,~ f_B>0\) |

| (P) | \(f\) increases if \(m\) is increased. |
| (Q) | \(f\) increases if \(F_A\) is increased. |
| (R) | \(f\) increases if \(F_R\) is increased. |
| 1. | \(\dfrac{E_m}{m}=\dfrac{E_M}{M}\) | 2. | \(mE_m=ME_M\) |
| 3. | \(\dfrac{E_m}{m^2}=\dfrac{E_M}{M^2}\) | 4. | \(m^2E_m=M^2E_M\) |



| 1. | \(W_1=W_2\) |
| 2. | \(W_1>W_2\) |
| 3. | \(W_1<W_2\) |
| 4. | Any of the above can be true |
| 1. | \(N\) increases as \(F\) increases. |
| 2. | \(N\) does not act through the center of the block. |
| 3. | \(f\) is greater than \(F.\) |
| 4. | \(f\) acts through the centre of the block. |
| 1. | \(m\dfrac{g+2a}{g+a}\) |
| 2. | \(m\dfrac{g+a}{g}\) |
| 3. | \(m\dfrac{g+a}{a}\) |
| 4. | \(m\dfrac{g+2a}{g}\) |