A wire of resistance R is coiled inductively so that its inductance is L. The impedance of the coil at a frequency of f is_______________?

Related Mcqs:

1. An inductive coil has a resistance of 100Ω. When an AC signal of frequency 1000Hz is fed to the coil the applied voltage leads the current by 45Ω. What is the inductance of the coil ?

   A. 10mH
   B. 12mH
   C. 16mH
   D. 20mH

2. 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

3. 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

4. An emf of 5 volt is produced by a self inductance, when the current changes at a steady rate from 3 to 2 ampere in 1 millisecond. The value of self inductance is_______?

   A. zero
   B. 5 H
   C. 5000 H
   D. 5 mH

   Submitted by: Tauseef Ali

5. What is the self-inductance of a coil in which an induced emf of 2V is set up when the current changes at the rate of 4 As-1 ?

   A. 0.5 mH
   B. 0.5H
   C. 2.0H
   D. 8.0H

6. 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)

7. A simple pendulum has a bob of mass m and its frequency is f. If we replaced the bob with a heavier one say of 2m then that will be its new frequency ?

   A. 1/4f
   B. 1/2f
   C. frequency lower than 20 Hz
   D. 2f

8. Coil of a galvanometer is suspended in a radial magnetic field so that the deflecting torque on the coil is always___________________?

   A. BINA cosa
   B. BINA sina
   C. BINA tana
   D. BINA

9. If the plane of the rectangular coil is parallel to the magnetic field (i.e radial magnetic field) the torque on the coil is_____________________?

   A. τ = NIAB cosφ
   B. τ = NIAB sinφ
   C. τ = NIAB tanφ
   D. τ = NIAB

10. If stretching force T of wire increases, then its frequency __________________?

    A. decreases
    B. increases
    C. remains the same
    D. any of above