Physics I 2069

Set A

Attempt all questions:

1. Discuss the motion of a charged of a charged particle in an alternating electric field. (7)

2. What do you mean by non-conservative forces? Also state an explain general law of conservation of energy. (2+2+3)

3. State and explain Gausses’ law. Apply it to find the field the field outside a uniformly changed sphere of radius a. (1+3+3)

4. What do you mean by displacement current ?Prove    (3.5+3.5)

5. Explain the term power and power factors .further discussion the phenomena of resonance and hence obtain quality factor. (2+2+2+1)

Set B

Attempt any eight questions:

6. Show the path of one projectile as seen from another projectile will always be a straight line. (4)

7. A rocket is moving upwards with acceleration 3g. Calculate the effective weight of astronaut sitting in the rocket when his actual weight is 75 Kg. (4)

8. A particle of mass m is moving along a circular path in a plane show that force action on it is conservative. (4)

9. The differential equation for a certain system is  ,find the time in which energy of the system falls to  times the initial value .(4)

10.A water drop is observed to fall through gas of density 0.001 gm/cc with a constant velocity of 980 cm/rec .What is the radius of the drop?(η for the gas = 2 × 10⁻⁴poise) (4)

11. Find the electric field at distance Z above the midpoint of a straight line segment of length 2L, which carries a uniform line chargeλ. (4)

12. Two parallel conducting plates are separated by the distance d and p.d.∆∅. A dielectric slab of dialectics constant K is and of uniform thickness is tightly fitted between the plates .find the electric filed in the dielectric.(4)

13. Find the vector potential of an infinite solenoid with N turns per unit length ,radius R and current I.(4)

14. The series combination of a resistance R and an inductance L is put in parallel with the series combination of resistance R and capacitance C. Show that if R² = L|C the impedance is independent of frequency.(4)

15. Consider a simple RL circuit in which a sudden voltage V is applied .Discuss its transient behavior and find the current as a function of time. (4)