Physics Class XII

Question 1. What is the work done in moving a charge of 10 nC between two points on an equipotential surface ? (1 mark)

Question 2. Name the device used for measuring the internal resistance of a secondary cell ? (1 mark)

Question 3. What is the nature of magnetic field in a moving coil galvanometer ? (1 mark)

Question 4. If a rate of change of current of 2 A/s induces an e.m.f.of 10mV in a solenoid, what is the self -inductance of the solenoid ? (1 mark)

Question 5. What type of magnetic material is used in making permanent magnets ? (1 mark)

Question 6. Two metals A, B have work-functions 2eV, 4eV respectively. Which metal has lower threshold wavelength for photoelectric effect ? (1 mark)

Question 7. Which have greater ionising power : alpha particles or beta particles ? (1 mark)

Question 8. Which part of the electromagnetic spectrum is used in operating a RADAR ? (1 mark)

Question 9. Which type of biasing gives a semiconductor diode very high resistance ? (1 mark)

Question 10. How is the luminosity of a star related to its radius ? (1 mark)

Question 11. An electric dipole, when held at 300 with respect to a uniform electric field of 10⁴N/C, experiences a torque of 9 x 10^-26Nm. Calculate the dipole moment of the dipole. (2 marks)

Question 12. A set of n identical resistors, each of resistance R ohm, when connected in series have an effective resistance X ohm and when the resistors are connected in parellel, their effective resistance is Y ohm. Find the relation between R, X and Y. (2 marks)

Question 13. State Kirchhoff's rules for eletrical networks. (2 marks)

Question 14. Show that Lenz's law is in accordance with the law of conservation of energy. (2 marks)

Question 15. Draw a labelled diagram of Hertz's experiment for producing electromagnetic waves. (2 marks)

Question 16. Give two differences between fringes formed in single slit diffraction and Young's double slit experiment. (2 marks)

Question 17. Light of wavelength 600nm is incident on an aperture of size 2mm. Calculate the distance up to which the ray of light can travel such that its spread is less than the size of the aperture. (2 marks)

Question 18. Explain the principle used in Bunsen's grease photometer to compare the illuminating powers of two light sources. (2 marks)

Question 19. A ray of light while travelling from a denser to a rarer medium undergoes total internal reflection. Derive the expression for the critical angle in terms of the speed of light in the respective media. (2 marks)

Question 20. Draw a graph showing the variation of binding energy per nucleon with mass number of different nuclei. Mark the region where the nuclei are most stable. (2 marks)