1. Kinetic energy of an electron accelerated by a potential difference of 1000 V is
2. A wire of radius R and uniform cross-section in has steady current i is flowing. The variation of the magnetic field as function of distance r from the axis of wire is correctly represented by
3. A bar magnet of magnetic moment M and pole strength m is broken in two equal part along the magnetic axis. The magnetic moment and pole strength of each part are
4. An electric bulbs of 100 W–300 V is connected with an AC supply of 500 V and Hz. The required inductance to save the electric bulb is
5. Which has the largest wavelength?
6. The graph between stopping potential (V0) versus frequency (v) of the light used in an experiment of photoelectric effect is as shown in figure. Work function of the metal surface is 7. In a nuclear reaction which of the following conservation is valid?
8. In a common emitter amplifier, when a signal of 40 mV is added to the input voltage the base current changes of 100 µA and emitter current changes by 2.1 mA, then the trans conductance is
9. For VHF television broadcasting, the frequency employed is generally
10. A,B,C and D are four points on an imaginary circle in region containing uniform electric field as shown in figure. Select the incorrect option 11. The resistance of a rectangular block of copper of dimensions 1 mm × 1 mm × 5 m between two square faces is 0.08 Ω. What is the resistivity of copper?
12. A square loop of side a carries a current I. A uniform magnetic field B is along the z-axis. This loop is placed in magnetic field in four different manners as shown in figures. Which manner corresponds to stable equilibrium?
13. The materials suitable for making electromagnets should have
14. A small square loop of wire of side l is placed inside a large circular loop of radius r. The loops are coplanar and their centre coincide. The mutual inductance of the system is proportional is
15. The ratio of secondary to the primary turns in a transformer is 5 : 4. If the power output be P, then the input power neglecting all loses must be equal to
16. In an electromagnetic wave, the amplitude of electric field is 1 V/m. What is average energy density of electric field?
17. Light travels through a glass (refractive index µ) plate of thickness t. If T is the time taken by light to travel the thickness of the plate then speed of light in vacuum is given by
18. From Brewster’s law for polarization, it follows that the angle of polarization depends upon
19. For Bohr’s first orbit of circumference 2πr, the de-Broglie wavelength of the revolving electron will be
20. The mass number of an atom A = 38 and its electronic configuration is 1s2 2s2 2p6 3s2 3p4. The number of neutrons and protons in the nucleus will be

21. If galvanometer shows null deflection in the given figure then the value of Y is .

22. The energy of 25 eV is required to remove one of the electrons from the neutral helium atom. The energy required to remove both the electrons from the helium atom .

23. White light is incident normally on an oil film of thickness 10–4 cm and refractive index 1.4. Which wavelengths will not be seen in the reflected system? .

24. A plano convex lens is silvered at its convex surface. The refractive index and the radius of curvature of the lens are and 30 cm respectively. Then the effective focal length will be .

25. The magnetic flux linked with a coil is given by a equation f (in webers) = 8t2 + 2t + 20. The induced emf in the coil at the end of third second will be  .