Four combinations of two thin lenses are given in List I. The radius of curvature of all curved surfaces is r and the refractive index of all the lenses is 1.5. Match lens combinations in List I with their focal length in List II and select the correct answer using the code given below the lists.
A block of mass m1 = 1 kg another mass m2 = 2 kg, are placed together (see figure) on an inclined plane with angle of inclination $$\theta$$. Various values of $$\theta$$ are given in List I. The coefficient of friction between the block m1 and the plane is always zero. The coefficient of static and dynamic friction between the block m2 and the plane are equal to $$\mu$$ = 0.3. In List II expressions for the friction on the block m2 are given. Match the correct expression of the friction in List II with the angles given in List I, and choose the correct option. The acceleration due to gravity is denoted by g.
[Useful information : tan (5.5$$^\circ$$) $$\approx$$ 0.1; tan (11.5$$^\circ$$) $$\approx$$ 0.2; tan (16.5$$^\circ$$) $$\approx$$ 0.3]
| List I | List II | ||
|---|---|---|---|
| P. | $$\theta = 5^\circ $$ |
1. | $${m_2}g\sin \theta $$ |
| Q. | $$\theta = 10^\circ $$ |
2. | $$({m_1} + {m_2})g\sin \theta $$ |
| R. | $$\theta = 15^\circ $$ |
3. | $$\mu {m_2}g\cos \theta $$ |
| S. | $$\theta = 20^\circ $$ |
4. | $$\mu ({m_1} + {m_2})g\cos \theta $$ |