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WorksheetsFIVIZZ WEEK 14: PHYSICS 4
Total questions: 12
Worksheet time: 13mins
What causes the Earth’s magnetic field?
The movement of liquid iron in the Earth’s outer core
The gravitational field of the Earth.
The permanent magnet in the Earth’s core.
State Lenz's law.
(a)
A positively charged particle moves at a velocity v perpendicular to a magnetic field B. If the magnitude of the velocity v is doubled, then the magnitude of the force F acting on the moving charge is
halved
doubled
quadrupled
quartered
not changed
What is the direction of the force acting on a negatively charged particle moving from East to West in a magnetic field directed downward?
directed to the right
directed to the left
directed upward
directed into the page
directed out of the page
A student makes three simple transformers, J, K and L.
Figure 3 shows how the potential difference across the secondary coil of each transformer varies as the potential difference across the primary coil of each transformer is changed. How can you tell that transformer J is a step-down transformer?
The potential difference across the secondary coil is smaller than the potential difference across the primary coil.
The potential difference across the secondary coil is bigger than the potential difference across the primary coil.
The potential difference across the primary coil is smaller than the potential difference across the secondary coil.
The potential difference across the primary coil is the same the potential difference across the secondary coil.
If a magnetic field B exerts a force F on a wire of length L with electric current in a magnetic field, then what value of the angle between the direction of the current i and the magnetic field B gives a maximum value for the magnitude of F?
180
45
90
120
0
In the diagram below, wire PQ is part of the closed circuit and is in a magnetic field B. If we neglect the resistance of the wires and the internal resistance of the battery, which of the following is true about the magnitude of the force acting on the wire PQ?
(I) It is proportional to the magnitude of the magnetic field B
(II) It is inversely proportional to R
(III) It is inversely proportional to E
(I) only
(I), (II) and (III)
(I), (II) and (III)
(I) and (II) only
(II) and (III) only
A teacher used the equipment shown in the figure below to demonstrate the motor effect.
The copper rod in the figure above has a length of 7 cm and a mass of 4 ×10-4 kg.
When there is a current of 1.12 A the resultant force on the copper rod is 0 N.
Calculate the magnetic flux density.
Gravitational field strength = 9.8 N/kg
1.00 T
2.50T
0.05T
4.40T
5.00T
Which of the following diagrams represents the directions of the forces acting on the two wires with current I flowing in the same direction as shown below?
If a force F is exerted on a charged particle when the particle enters a magnetic field B at a velocity v, which of the following is always true?
Vectors F, B and v are all perpendicular to each other
Vectors F and B are parallel
Vectors F and B are perpendicular
Vectors F and v are be parallel
Vectors B and v may perpendicular
A straight wire carries a current directly into your computer screen. In what direction would the magnetic field be?
Out of the screen
Clockwise
Counter-clockwise
Into the screen
Right to left
A negatively charged particle q enters from the left an area with both an electric field directed downward and a magnetic field of magnitude 6.0×10-6 T directed into the page (see figure below). What must be the magnitude of the electric field so that the particle is not deflected if the magnitude of its velocity is 2.0×105 cm/s?
1.2 v/m
3.3 × 10-11 v/m
1.2 × 10-2 v/m
3.3 × 1010 v/m
120 v/m
