Two identical metal balls with charges + 2Q and – Q are separated by some distance, and exert a force F on each other. They are joined by a conducting wire, which is then removed. The force between them will now be_________?

Related Mcqs:

1. When a force is applied at one end of an elastic wire it produces at strain ∝ in the wire. If y is the youngs modulus of the material of the wire the amount of energy stored per unit volume of the wire is given by_________________?

   A. Y∝
   B. 2Y∝
   C. Y∝/2
   D. Y∝2

2. A wire suspended vertically from one end is stretched by attaching a weight of 20N to the lower end. The weight stretches the wire by 1mm. How much energy is gained by the wire ?

   A. 0.01J
   B. 0.02J
   C. 0.04J
   D. 1.0J

3. A wire of length L is stretched by a length E when a force F is applied at one end. If the elastic limit is not exceeded the amount of energy stored in the wire is_________________?

   A. FE
   B. (FE)
   C. FE2/L
   D. FE2

4. A wire is stretched by a force F which causes an extension 1. The energy stored in the wire is____________________?

   A. The extension of the wire is proportional to the force applied
   B. The weight of the wire is negligible
   C. The wire is not stretched beyond its elastic limit
   D. The cross sectional area of the wire remains constant

5. A uniform steel wire of length 4m and area of cross-section 3×10-6m2 is extended by 1mm by the application of a force. If the youngs modulus of steel is 2×1011 Nm-2 the energy stored in the wire is___________________?

   A. 0.025J
   B. 0.50J
   C. 0.75J
   D. 0.100J

6. What is the value of the current in a wire of 10cm long at the right angle to a uniform magnetic field of 0.5 Weber/m2 when the force acting on the wire is 5N ?

   A. 1A
   B. 10A
   C. 100A
   D. 1000A

7. A wire obeys Hooks law is of length 11 when it is in equilibrium under a tension F1. Its length becomes 12 when the tension is increased to F2. The energy stored in the wire during this process is____________________?

   A. (F1+F2) (121+122)
   B. (F1+F2) (122-112)
   C. (F1+F2) (12-11)
   D. (F1+F2) (12-11)

8. When two bodies move toward each other with constant speeds the distance between them decreases at the rate of 6m / sec. If they move in the same direction the distance between them increases at the rate of 4m/sec. Then their speeds are________________?

   A. 5m/s, 1m/s
   B. 3m/s, 3m/s
   C. 6m/s, 1m/s
   D. 4m/s, 2m/s

9. When two charges are placed in water then the Coulomb force between them reduces to _____________?

   A. 1/2 times
   B. 1/3 times
   C. 1/78 times
   D. 1/58 times

   Submitted by: M.Irfan

10. In optic fiber transmission the repeater are separated through a distance of __________ km in newer system?

    A. 300km
    B. 200km
    C. 100km
    D. 20km