UPSEE - 2001 Full Paper
Section-1 Phusics 1. A sphere, a cube and a thin circular plate, all made of the same meterial and having the same mass are initially heated to a temperature of 1000°C. Which one of these will cool first ? 1) Plate 2) Sphere 3) Cube 4) None of these 2. A beam of light composed of red and green rays is incident obliquely at a point on the face of a rectangular glass slab. When coming out on the opposite parallel face, the red and green rays emerge from : 1) two points propagating in two different non-parallel directions 2) two points propagating in two different parallel directions 3) one point propagating in two different directions 4) one point propagating in the same direction 3. Two wires having resistances of 2 and 4Ω are connected to same voltage. The ratio of Ω heat dissipated in the resistances will be : 1) 4 : 3 2) 1 : 2 3) 5 : 2 4) 2 : 1 4. A photon moves to energy level E1 from E2 to find more stable nucleus, then the frequency will be : 1) exactly (E2 - E1)/h 2) slightly greater than (E2 - E1)/h 3) slightly less than (E2 - E1)/h 4) hv 5. At 273°C, the emissive power of a perfect black body is R. What is its value at 0°C ? 1) R/4 2) R/16 3) R/2
4) None of these 6. Among two discs A and B, first have radius 10 cm and charge 10-6 C and second have radius 30 cm and charge 10-5 C. When they are touched, charges on both are qA and qB respectively, will be : 1) qA = 2.75 μC, qB = 3.15 μC 2) qA = 1.09 μC, qB = 1.53 μC 3) qA = qB = 5.5 μC 4) none of these 7. The potential difference between the cathode and the target electrode in a coolidge tube is 24.75 kV. The minimum wavelength of the emitted X-rays is : 1) 0.1 Å 2) 0.5 Å 3) 1 Å 4) 5 Å 8. The first named planetoid (ceres) has its orbit in between the orbits of : 1) mars and jupiter 2) neptune and pluto 3) mercury and pluto 4) venus and saturn 9. A torque of 10-5 Nm is required to hold a magnet at 90° with the horizontal component of the earth's magnetic...