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WorksheetsP.3.7.5.3 Magnetic flux and flux linkage
Total questions: 11
Worksheet time: 6mins
A rectangular coil of area A has N turns of wire. The coil is in a uniform magnetic field of flux density B with its plane parallel to the field lines. The coil is then rotated through an angle of 30° about axis PQ. What are the correct initial value and correct final value of the magnetic flux linkage?
A
B
C
D
The diagram shows a coil placed in a uniform magnetic field. In the position shown, the angle between the normal to the plane of the coil and the magnetic field is π/3 rad.
A
B
C
D
A rectangular coil of area A has N turns of wire. The coil is in a uniform magnetic field, as shown in the diagram.
When the coil is rotated at a constant frequency f about its axis XY, an alternating emf of peak value ε0 is induced in it.
What is the maximum value of the magnetic flux linkage through the coil?
π f ε0
2π f ε0
The graph shows how the magnetic flux, Φ, passing through a coil changes with time, t.
Which one of the following graphs could show how the magnitude of the emf, V, induced in the coil varies with t?
A 500 turn coil of cross-sectional area 4.0 × 10–3 m2 is placed with its plane perpendicular to a magnetic field of flux density 7.5 × 10–4 T. What is the value of the flux linkage for this coil?
3.0 × 10–6 Wb turns
1.5 × 10–3 Wb turns
0.19 Wb turns
94 Wb turns
A bar magnet is pushed into a coil connected to a sensitive ammeter, as shown in the diagram, until it comes to rest inside the coil.
Why does the ammeter briefly show a non-zero reading?
The magnetic flux linkage in the coil increases then decreases.
The magnetic flux linkage in the coil increases then becomes constant.
The magnetic flux linkage in the coil decreases then increases.
The magnetic flux linkage in the coil decreases then becomes constant.(
A coil of 50 turns has a cross-sectional area of 4.2 × 10–3 m2. It is placed at an angle to a uniform magnetic field of flux density 2.8 × 10–2 T, as shown in the diagram, so that angle θ = 50°.
What is the change in flux linkage when the coil is rotated anticlockwise until θ = 0°?
The flux linkage decreases by 2.1 × 10–3 Wb turns.
The flux linkage increases by 2.1 × 10–3 Wb turns.
The flux linkage decreases by 3.8 × 10–3 Wb turns.
The flux linkage increases by 3.8 × 10–3 Wb turns.
An aircraft, of wing span 60 m, flies horizontally at a speed of 150 m s–1. If the vertical component of the Earth’s magnetic field in the region of the plane is 1.0 × 10–5 T, what is the magnitude of the magnetic flux cut by the wings in 10 s?
1.0 × 10–5 Wb
1.0 × 10–4 Wb
9.0 × 10–2 Wb
9.0 × 10–1 Wb
The graph shows how the magnetic flux passing through a loop of wire changes with time. What feature of the graph represents the magnitude of the emf induced in the coil?
the area enclosed between the graph line and the time axis
the area enclosed between the graph line and the magnetic flux axis
the inverse of the gradient of the graph
the gradient of the graph
The magnetic flux through a coil of N turns is increased uniformly from zero to a maximum value in a time t. An emf, E, is induced across the coil. What is the maximum value of the magnetic flux through the coil?
E t N
Which line, A to D, gives correct units for both magnetic flux and magnetic flux density?
A
B
C
D
