Electrostatics : Rivision Question paper

Electrostatics -12th Grade : (8/12/2011) -----------------------------------1. Two charges q1 and 12 repel each other if....q1x q2 >0 2. when an electric dipole is placed in a uniform electric field such that the axis of the dipole is parallel to the electric field, the Torque is.... and Translational force is.... Zero, Zero 3. In the above circuit, all capacitors are 4 micro Farad. What is the effective capacity across A and C...... Ans. 8 micro Farad 4. A 250 V battery is connected across two capacitors of capacitance 2 micro Farad and 5 micro Farad joined in parallel. Calculate the charge and energy stored in each capacitors? Ans. 500 micro Coulomb, 1250 micro Coulomb 5. What is the absolute permittivity of water if its dialectic constant is 80? Ans. 7.08 x 10-10 6. Two point charges whose magnitudes are in the ratio 2:3 seperated by 2cm repel each other with a force 3375 N. Find the magnitude of the charges? Ans. 10 micro columb and 15 micro columb 7. If an electron is accelerated by a p.d. of 100V, calculate the velocity acquited by it. Mass of an electron =9.1 x 10-31 kg and charge of electron is 1.6 x 10-19 C8. Calculate the capacitance of the earth , when it is taken as spherical conductor of radius 6400 Km. 9. Effective capacitance of two capacitors when connected in series and in parallel are 2 micro farad and 9 micro farad. Find the individual capacitance ? 10. What are equipotential surfaces ? Write examples of equipotential surfaces ? * * * * * * * * * *