1. If the wavelength of a-line of Lyman series in hydrogen atom is , find the wavelength of -line of Paschen series. 3256 (b) 36x5 22 (c) 3522 26 (d) 32 x5 26 2. If temperature of a liquid is increased, choose the correct option regarding change in its surface tension and viscosity. (a) Surface tension decreases while viscosity increases (b) Surface tension increases while viscosity decreases (c) Both increases (d) Both decreases 3. A proton of mass m and charge q enters a region of uniform magnetic field of a magnitude B with a velocity v directed perpendicular to the magnetic field. It moves in a circular path and leaves the magnetic field after completing a quarter of a circle. The time spent by the proton inside the magnetic field is proportional to: (a) 1-1/2 4. (b) 1-1/2 (c) 10 (d) v Abhishek and Deepak have two samples of magnetic materials X and Y. Experimentally they determine the following properties of the samples. Retentivity Coercivity X 1.5T Y 1.0 T 20 Am 100 Am Considering this, choose best choice (a) X and Y both for electromagnets (b) X for electromagnetic and Y for permanent magnets (c) X and Y both for permanent magnets (d) X for permanent magnets and Y for electromagnets 5. Three thin rods of mass m and length a each are joined to form a triangle ABC in vertical plane. The triangle is pivoted at the vertex A such that it can rotate in the vertical plane. It is released from rest when the side AB is horizontal as shown. As the triangle rotates, the maximum velocity of the vertex B, VMAX, is given by: A B (a) vmax: 4ga = (b) vmax = 3ga (c) vMax: 2ga (d) v MAX=ga 3