Question

1. A total charge of 3.35 C is distributed on two metal spheres. When the spheres are 10.00 cm apart, they each feel a repulsive force of 4.5*10^11 N. How much charge is on the sphere which has the lower amount of charge?

2. 2 equal charges, 15 micro Coulomb each, are separated by 5 cm. Find force between those.

3. Add 5 micro Coulombs and 7,098 nano Coulombs and get the result in nano Coulombs unit.

4. How many excess electrons can be counted in a rubber rod of - 2 *0.00001 nano Coulombs of charges?

5. A metal ball has - 4 Coulomb of charge. If it receives 0.50*10^20 number of electrons, what will be the resultant charge of the ball?

6. 2 equal charges are seperated by 37 mm and experiences a repulsion force of 9 Newton. Calculate the amount of each charge in micro Coulombs.

7. 2 equal charges, 132 micro Coulombs each, experiences an attraction force of 132 Newton. Calculate the distance between the charges in mm.

8. What is the total charge of all protons in 8 gram of water (H2O)?

9. 3 charges, 2 µC each, are located on three vertices A, B, C of an equilateral triangle with sides 1 cm each. Another charge q is located at the mid point D of the side BC. Calculate q in micro Coulomb so that net force on the charge at A due to the charges at B, C and D is zero.

10. In a right angle traingle ABC, angle ABC is 90 Degree, AB = 2 m, and angle ACB is 41.81 Degree. A point charge of 5*43 nC is placed at point C, point charge 4* 43 nC is placed at point A and point charge 1 C is placed in point B. Calculate the force on charge at B due to others two.

11. What is the total charge of all electrons in 8 /100 gram of Carbon dioxide CO2 gas?

12. Two equal charges with magnitude Q and Q experience a force F1 when held at a distance r. F2 is the force between two charges of magnitude 3*Q and 4*Q when held at a distance r/4? What is the ratio of F2 to F1?

Answer 1

q_1 + q_2 = 3.35 C force, f = k q_1 q_2/r^2 r = 10 cm = 0.1 m 4.5 times 10^11 = 9 times 10^9 times q_1 (3.35 - q_1/(0.1)^2 0.5 = q_1 (3.35 - q_1) 0.5 = 3.35 q_1 - q_1^2 q_1^2 - 3.35 q_1 + 0.5 = 0 q_1 = 3.1934 , 0.1566 Therefore Lower charge is = 0.1566 C Tilde Equal 0.16 C (2) Force b/w two charges is given by F = kq_1 q_2/r^2 where k = 1/4pi e_0 = 9 times 10^9 = 9 times 10^9 times (15 times 10^-6)^2/(5 times 10^-2)^2 = 810 N (3) q = q_1 + q_2 = (5 times 10^-6) + (7098 times 10^-9) C = (5000 times 10^-9) + (7098 times 10^-9) C = 12098 times 10^-9 C = 12098 nC