The electromagnet has 50 turns and a current of 1A flows through the coil. If the length of the magnet circuit is 200 mm, what is the magnetic field strength ?

Related Mcqs:

1. A certain amount of current flows through a ring-shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil ?

   A. Decreases
   B. Increases
   C. Remains same
   D. First increases and then decreases depending on the depth of iron in¬sertion

2. A 200 turn coil having an axial length of 30 mm and a radius of 10 mm is pivoted in a magnetic field having a flux density of 0.8 T. If the coil carries a current of 0.5 A, the torque acting on the coil will be_____________?

   A. 8 N-m
   B. 0.48 N-m
   C. 0.048 N-m
   D. 0.0048 N-m

3. A rectangular magnet of magnetic moment M is cut into two piece of same length, the magnetic moment of each piece will be______________?

   A. M
   B. M/2
   C. 2 M
   D. M/4

4. What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m ?

   A. 2 AT
   B. 4 AT
   C. 6 AT
   D. 10 AT

5. What will be the current passing through the ring shaped air cored coil when number of turns is 800 and ampere turns are 3200 ?

   A. 2
   B. 4
   C. 6
   D. 8

6. In a simple magnetic field the strength of magnet flux_______________?

   A. is constant and has same value in energy part of the magnetic field
   B. increases continuously from initial value to final value
   C. decreases continuously from initial value to final value
   D. first increases and then decreases till it becomes zero

7. A square cross-sectional magnet has a pole strength of 1 x 10 Wb and cross sectional area of 20 mm x 20 mm. What is the strength at a distance of 100 mm from the unit pole in air ?

   A. 63.38 N/Wb
   B. 633.8 N/Wb
   C. 6338 N/Wb
   D. 63380 N/Wb

8. When a magnet is in motion relative to a coil the induced e.m.f. does not depend upon____________?

   A. resistance of the coil
   B. motion of the magnet
   C. number of turns of the coil
   D. pole strength of the magnet

9. How does the magnetic compass needle behave in a magnetic field ?

   A. It assures a position right angle to magnetic field
   B. It starts rotating
   C. It assures a position which follows a line of magnetic flux
   D. None of the above

10. A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be______________?

    A. zero
    B. BLI
    C. B2LI
    D. BLI2