Physics

4. A semiconductor has generally ______ valence electrons.
6. The electric field lines for an electric dipole emerge from ______ charge.
8. In transformer, the core is made up of soft iron in order to pass the maximum __________________.
9. The photoelectric emission could be explained by the ________ nature of line.
11. When a pure semiconductor is heated, its resistance ____________.
12. The metal detector works on the principle of _________ in an a.c. circuit.

1. The ______ to the magnetic field lines at any point gives the direction of the magnetic field at that point.
2. The ratio of electric flux density to electric field intensity is known as _______.
3. In a cyclotron the charged particles move along a _______ path under the action of a perpendicular magnetic field.
5. In electromagnetic induction, the induced e.m.f. in a coil is independent of _________ of the circuit.
7. Dispersion of light is caused due to dependence of its speed on ___________.
10. Photoelectric current depends on ________ of incident light.