Question 7.16: The total core loss of a specimen of silicon steel is found ...

Basic Electrical Engineering

The total core loss of a specimen of silicon steel is found to be 1500 W at 50 Hz. Keeping the flux density constant, the loss becomes 3000 W when the frequency is raised to 75 Hz. Calculate separately the hysteresis and eddy-current loss at each of these frequencies.

The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

Related Answered Questions

Question: 7.ASP.19

In the magnetic circuit of Fig. 7.34, the relative permeability of the core steel is 2000. Calculate (a) the maximum flux density (b) the maximum value of exciting current (c) the maximum value of the energy stored in the magnetic circuit. What percentage of it resides in the air-gap? Assume zero ...

Verified Answer:

(a) The coil induced emf equals applied voltage [l...

Question: 7.18

Three coils are wound on a cast steel core as shown in Fig. 7.33. The current directions in coils are indicated in the figure core data.Cross-sectional area, A_c = 12 cm² Mean path length, I_c = 30 cm Coils data A 200 turns, 1A B 600 turns, 0.75 A C ? 0.5 A How many turns should coil C have create ...

Verified Answer:

Core flux = 1.5 mWb Core cross-section = 12 cm² Co...

Question: 7.17

A rectangular ring ferromagnetic material has a 16-cm inner diameter a 20-cm outer diameter and 2.5-cm thickness. A coil of 750 turns is wound on the ring. It is found that to produce a flux of 1.25 m Wb, the coil must carry 1 A. Find the following quantities:(a) mmf (b) magnetic field intensity ...

Verified Answer:

(a) mmf, F = 750 × 1 = 750 AT (b) Mean dia = [la...

Question: 7.15

A toroid is composed of three parts of different materials but of uniform cross-sectional area. Their mean length and relative permeability are:I_1 = 0.15 m, µ_r1 = 1447 (cast steel) I_2 = 0.30 m, µ_r2 = 5969 (mild silicon steel) I_3 = 0.45 m, µ_r3 = 47750 (nickel iron) It is required to establish ...

Verified Answer:

(a) Flux density B =

\frac{\phi }{A} = \fra...

Question: 7.14

A magnetic circuit has a mean core length of 160 cm and uniform cross-section of 5 cm² . It has an air-gap of 0.8 mm and is wound with a coil of 1200 turns. Determine the self-inductance of the coil if the core material has a relative permeability of 1600. ...

Verified Answer:

The core reluctance is

R_{c} = l_{c} / μ_{0...

Question: 7.13

A square loop of sides 2d is placed with its sides parallel to an infinitely long conductor carrying current I. The centre line of the square is at a distance b form the conductor. Determine the expression for the total flux passing through the loop.What would be the loop flux if the loop is placed ...

Verified Answer:

With reference to Fig. 7.31, at a distance r from ...

Question: 7.12

For the magnetic circuit of Fig. 7.30, find I2 , V2 and V2 / V1. ...

Verified Answer:

Writing the mesh equation for the two meshes, we h...

Question: 7.11

An attracted armature relay shown in Fig. 7.29 (a) has an air-gap of x = 0.05 mm. It magnetization curve in open and closed position is given in Fig. 7.29 (b). Observe that it is linear.(a) If the relay armature move very fast from open to closed position, find the mechanical work done. Where does ...

Verified Answer:

Note: AT vs

\phi

plot will be the ...

Question: 7.10

The energy stored per unit volume of magnetic field in air is B²/2µ_0.Derive the expression for the force of attraction between two magnetized surface with air in between.A U-shaped lifting magnet made of cast steel is wound with an exciting coil of 1000 turns. It is required to lift a steel mass ...

Verified Answer:

W_{ƒ}

(air) =

\frac{B²}{...

Question: 7.9

A ring of magnetic material has rectangular cross-section. The inner diameter of the ring is 20 cm and the outer diameter 25 cm, its thickness being 2 cm. An air-gap of 1 mm length is cut across the ring. The ring is wound with 500 turns carrying a current of 2 A. The permeability of the magnetic ...

Verified Answer:

Area of cross-section of ring =

\frac{5}{2}...