1. If switch is open then null point is 4 m away from A end. What will be distance of null point from A end, if switch is closed ?

2. The ratio of power gain and resistance gain in case of common-base amplifier is :-
3. Find value of I :

4. The correct relation for α, β for a transistor is:-
5. Resistance of a galvanometer 50Ω and its current range is 10–4A. We want to measure maximum 4V with this meter. Find value of series resistance to be connected :-
6. The light emitting diode (LED) :-
7. Two concentric metallic shells are given in fig. Inner shell is given 2Q charge and outer thick shell is given 3Q charge. Potential on the centre
is :-

8. The electrical conductivity of pure germanium increasing the temperaturecan be increased by :-
9. A half-ring of radius r has linear charge density λ. The electric potential at the centre of the halfring is :-
10. Identify the part X in following block diagram of a reciever in AM. :-

11. Two identical metal balls with charges + 2Q and –Q are separated by some distance, and exert a force F on each other. They are joined by a
conducting wire, which is then removed. The force between balls will be :-
12. By what percentage will the transmission range of a TV tower be affected when height of tower is increased by 21% :-
14. In following radioactive reaction which element is formed-

7N14 +2He41H1+ ?
15. Two condensers 1μF & 2μF in a circuit are joined as shown in figure. The potential of point P & Q are 3 kV & 1 kV respectively. The potential of
point R will be :-

16. If binding energies per nucleon of X, B and A are 7.4 MeV, 8.2 MeV and 8.2 MeV respectively, then the energy released in the reaction :

X200 → A110 + B90 + energy will be-
17. As shown in figure two identical capacitors are connected to a battery of V volts in parallel.

When capacitors are fully charged then sum of their stored energy is U1. If the key K is opened and a material of dielectric constant ∈r = 2 is
inserted in each capacitors then sum of their stored energy is U2. Then  \mathrm{\frac{{{U_1}}}{{{U_2}}}\ } will be :–
18. What is the power output of 92Y235 reactor if it takes 30 days to use up 2 kg of fuel and if each fission gives 188 MeV of usable energy -
19. A point charge Q is placed at origin if electric field at A and B is \mathrm{{\overrightarrow E _1}\,and\,{\overrightarrow E _2}\,then\,\left| {{{\overrightarrow E }_1} - {{\overrightarrow E }_2}} \right|\ } is :-

20. The nucleus 92X234 decays by emitting 3a and 1βparticle. Final product is-
21. A circuit is arranged as shown. Then, the current from A to B is :

22. Two elements P and Q each of mass 10–2 kg are present in a given sample. The ratio of their atomic weights is 1 : 2 and the half lives are 4s and 8s respectively. The masses of P and Q present after 16s will be respectively-
23. A man's near point is 0.5 m and far point is 3m. Power of spectacles lenses required for -

(i) reading purposes

(ii) seeing distant objects, respectively, are :-
24. The radioactive rays can be detected by their action on photographic film. A radioactive sample enclosed in an enclosure produces a spot on a photographic film. When a perpendicular magnetic field is applied to the enclosure, how many spots are observed on the photographic film-
25. A light ray is incident perpendicular to one face of a 90° prism and it totally internally reflected at the glass - air interface. If the angle of
reflection is 45°, we conclude that the refractive index n is :-

26. The inductive time constant is -
27. The plane faces of two identical plano - convex lenses each having a forcal length of 50 cm are placed against each other to form a usual
bioconvex lens. The distance from this lens combination at which an object must be placed to obtain a real, inverted image which has the
same size as the object, is :-
28. The power in ac circuit is given by P = ErmsIrms cos f. The value of power factor cos f in LCR circuit at resonance is -
29. The focal lengh of field achromatic combination of telescope is 90 cm. The dispresive powers of lenses are 0.024 and 0.036 respectively. Their
focal length will be:-
30. A conductor rod AB moves parallel to X-axis in a uniform magnetic field, popinting in the positive Z-direction. The end A of the rod gets

31. In Young's double slit experiment carried out with light of wavelength λ = 5000Å, the distance between the slits is 0.2 mm and the screen is at 200 cm from the plane of slits. The central maximum is at x = 0. The third maximum will be at x equal to :-
32. The hardness of a magnetic material is stated on the basis of the following property of the material-
33. When the angle of incidence on a material is 60°, the reflected light is completely polarised. The velocity of the refracted ray inside the material is (in ms–1):-
34. In the figure A, B and C, are current carrying wires. The direction of resultant force on the wire B will be -

35. The main difference in the phenomenon of interference and diffraction is that :-
36. The magnetic field at point O due to current carrying wire bent in the shape shown in figure is-

37. For the isolated charged conductor shown in Fig. the potentials at points A, B, C and D are VA, VB, VC and VD respectively. Then-

38. According to the figure shown, a current carrying wire and a rectangular loop are placed close to each other, then-

39. An electric dipole consisting of two opposite charges of 2 × 10–6 C each separated by a distance of 3 cm is placed in an electric field of 2 × 105 newton per coulomb. The maximum torque on the dipole will be -
40. For the circuit shown in fig VC – VE is-

41. For a uniformly charged sphere of radius R which of following shows a correct graph between the electric field intensity and the distance from the centre of sphere -

42. The effective resistance (in Ω) between B and C of letter A containing resistances as shown in fig is -

43. A parallel plate capacitor with plate area A and separation dielectric slabs of equal thickness as shown in fig. The dielectric constants are K1 and K2. The capacitance of this arrangement is

44. When a piece of aluminium wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance
will become-
45. A full-wave rectifier circuit along with the output is shown in figure. The contribution(s) from the diode 1 is(are) :-