CLASS XII CH 1 ELECTRIC CHARGE AND FIELD SHEET.pdf

CLASS XII ELECTRIC CHARGES AND FIELD 2022 1. If 1014 electrons are removed from a neutral metal sphere, then what is the charge on the sphere? 2. What is the total charge on 75 kg of electrons? 3. How much positive and negative charge is there in a water molecule?...

CLASS XII ELECTRIC CHARGES AND FIELD 2022 1. If 1014 electrons are removed from a neutral metal sphere, then what is the charge on the sphere? 2. What is the total charge on 75 kg of electrons? 3. How much positive and negative charge is there in a water molecule? 4. Two positively charged particles, each of mass 1.7 × 10 -27 kg and each carrying a charge of 1.6 × 10-19 C are placed r distance apart. If each one experiences a repulsive force equal to its weight then find r. 5. Two fixed charges +4q and +q are at a distance 3 m apart. At what point between the charges, a third charge +q must be placed to keep it in equilibrium? 6. Four charges Q , q , Q and q are kept at the four corners of a square as shown below. What is the relation between Q and q so that the net force on a charge q is zero? 7. Calculate the electric field strength required just to support a water drop of mass 10 -7 kg having a charge 1.6 × 10-19 C. 8. An electron falls through a distance of 1.5 cm in a uniform electric field of magnitude 2 × 104 N/C. Now the direction of the field is reversed keeping the magnitude uncharged and a proton falls through the same distance. Compute the time of fall in each case, neglecting gravity. 9. Calculate the magnitude of an electric field which can just suspend a deuteron of mass 3.2 × 10-27 kg freely in air. 10.Two point charges of 5 𝜇C and 20 𝜇C are separated by a distance of 2 m. find the point on the line joining them at which electric field intensity is zero. 11.A rectangular surface of sides 10 cm and 15 cm is placed inside a uniform electric field of 25 N/C, such that normal to the surface makes an angle of 60o with the direction of electric field. Find the flux of electric field through the rectangular surface. 12.The electric field in a certain region of space is 5𝚤̂ + 4𝚥̂ − 4𝑘 × 10 N/C. calculate electric flux due to this over an area of ( 2𝚤̂ − 𝚥̂ ) × 10 m2. 13.Two opposite charges each of magnitude 2 𝜇C are 1 cm apart. Find electric field at a distance of 5 cm from the mid - point on axial line of the dipole. Also find the field on equatorial line at the same distance from mid – point. 14.Two charges + 20 𝜇C and – 20 𝜇C are 5 mm apart. Find the electric field on axial as well as on the equatorial line at a distance 20 cm from the mid – point of the dipole. 15.An electric dipole of length 10 cm having charges + 6 × 10-3 C and – 6 × 10-3 C, placed at 30o with respect to a uniform electric field experiences a torque of magnitude 6√3 Nm. Calculate the magnitude of electric field.