Electrical Engineering - Magnetism and Electromagnetism

Exercise :: Magnetism and Electromagnetism - General Questions

6. 

What is the reluctance of a material that has a length of 0.07 m, a cross-sectional area of 0.014 m2, and a permeability of 4,500 Wb/At × m?

A. 1111 At/Wb
B. 111 At/Wb
C. 11 At/Wb
D. 1 At/Wb

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

7. 

A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will

A. increase
B. decrease
C. remain constant
D. be excessive

Answer: Option B

Explanation:

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8. 

What is the flux density when the flux is 5.5 Wb and the cross-sectional area is 6 × 10–3 m2?

A. 91.7 T
B. 917 T
C. 91 T
D. 9.7 T

Answer: Option B

Explanation:

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9. 

The unit for reluctance is

A. tesla
B. At/Wb
C. At/m
D. Wb

Answer: Option B

Explanation:

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10. 

If the steel disk in a crankshaft position sensor has stopped with the tab in the magnet's air gap, the induced voltage

A. increases
B. decreases
C. is zero
D. will remain constant

Answer: Option C

Explanation:

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