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___________________?

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 rubber cord of cross-sectional area 2cm2 has a length of 1m. When a tensile force of 10N is applied the length of the cord increases by 1cm. What is the youngs modulus of rubber ?

   A. 2×108 Nm-2
   B. 5×106 Nm-2
   C. 0.5×10-6 Nm-2
   D. 0.2×10-6Nm-2

4. 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

5. 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)

6. 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

7. A wire of uniform area of cross-section A length L and resistance R is cut into two parts. Resistivity of each part _________________?

   A. remains the same
   B. is doubled
   C. is halved
   D. becomes zero

8. 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

9. The ration stress to strain in youngs modulus of the material then tension is__________________?

   A. Directly proportional to extension
   B. Directly proportional to strain
   C. Directly proportional to square of amplitude
   D. Inversely proportional to extension

10. Force 100N is applied on a wire produces extension 5mm in it. Energy stored in it is

    A. 0.125 J
    B. 0.250 J
    C. 0.50 J
    D. 1 J

    Submitted by: Huzaifa Naseer