SOLVED PAPER

DPMT - 2005 1. S.I. unit of magnetic flux is (a) tesla (b) oersted (c) weber (d) gauss.

2. A body of mass m is moving towards east and another body of equal mass is moving towards north. If after collision both stick together, their speed after collision would be (a) v (b) v/2

(c) 72 v (d) v /72

3. A body of mass 1 kg is moving in a vertical circular path of radius 1 m. The difference between the kinetic energies at its highest and lowest position is (a) 20 J (b) 10 J

(c) 475 J (d) 10(75-1) J

4. Across each of two capacitors of capacitance 1 |iF and 4 [J.F, a potential difference of 10 V is applied. Then positive plate of one is connected to the negative plate of the other, and negative plate of one is connected to the positive plate of the other. After contact, (a) charge on each is zero (b) charge on each is same but non-zero (c) charge on each is different but non-zero (d) none of these.

5. Magnification of a compound microscope is 30. Focal length of eye piece is 5 cm and the image is formed at a distance of distinct vision of 25 cm. The magnification of the objective lens is (a) 6 (b) 5 (c) 7.5 (d) 10.

6. Kirchoff's law of junction, 2 / = 0, is based on (a) conservation of energy (b) conservation of charge (c) conservation of energy as well as charge (d) conservation of momentum.

7. Calculate the amount of heat (in calories) required to convert 5 g of ice at 0°C to steam at 100°C . (a) 3100 (b) 3200

(c) 3600 (d) 4200.

8. A transverse wave is expressed as : y = y0s'm2nft. For what value of A,, when maximum particle velocity is equal to 4 times the wave velocity? (a) y0n/2 (b) 2y0n (c) y0n (d) y0n/4.

9. Two bodies are thrown up at angles of 45° and 60°, respectively, with the horizontal. If both bodies attain same vertical height, then the ratio of velocities with which these are thrown is (a) 7273 (b) 2 /73

( C ) 7 5 7 2 ( d ) 7 3 / 2 •

10. Charges 40 , q and 0 are placed along x-axis at positions x-Q,x = U2 and x = I, respectively. Find the value of q so that force on charge 0 is zero. (a) Q (b) 0/2 (c) - 0 / 2 (d) - 0 .

11. A ray fall on a prism ABC (AB - BC) and traval as shown in figure. The least value of refractive index of material of the prism, should be (a) 1.5 (b) 72 (c) 1.33

(d) 7 3

12. Escape velocity from a planet is v„. If its mass is increased to 8 times and its radius is increased to 2 times, then the new escape velocity would be

(a) v„ (b) 72vc

(c) 2v„ (d) 272vc

13. A body takes time t to reach the bottom of an inclined plane of angle 8 with the horizontal. If the plane is made rough, time taken now is 21. The coefficient of friction of the rough surface is

* based on memory

32 PHYSICS l"'OH YOU | AUGUST '05 30