Practice Topic D - Fields with authentic IB Physics exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like mechanics, thermodynamics, and waves. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
SLPaper 2
A satellite orbits a planet of mass at a radius of from the planet’s centre. The satellite has a mass of .
1.[2]
Calculate the gravitational force acting on the satellite.
2.[2]
Determine the orbital speed of the satellite.
3.[2]
Calculate the total energy of the satellite in its orbit.
4.[1]
Explain how the energy of the satellite would change if its orbit gradually decays.
Question 2
SLPaper 2
The diagram shows a straight conductor carrying an electric current into the page, as indicated by the arrow and dot. The circles with crosses represent a uniform magnetic field directed into the page.
1.[1]
State the direction of the magnetic field created by the current in the wire.
2.[2]
Describe the interaction between the magnetic field created by the current and the uniform magnetic field.
3.[2]
Outline what would happen to the net magnetic field at points above and below the wire.
4.[1]
Suggest one way to increase the magnetic effect of the current in the wire.
Question 3
HLPaper 2
The diagram shows two point masses: mass and mass . Point lies between them, at a distance from mass and from mass B.
1.[1]
State the condition for the net gravitational field at point to be zero.
2.[2]
Show that the magnitudes of the gravitational fields due to each mass at point are equal.
3.[2]
If and , calculate the magnitude of the gravitational field at due to mass .
4.[2]
If a test mass were placed at point , describe qualitatively what would happen if it were slightly displaced toward mass A.
Question 4
HLPaper 2
Two point charges, and , are separated by a distance of .
1.[2]
Calculate the electric potential at a point P located from and from .
2.[2]
Determine the work done to bring a charge from infinity to point P.
3.[2]
Calculate the electric field strength at point P due to each charge and determine the net electric field vector at point P. (Assume the geometry places the field vectors at to one another.)
4.[1]
Find the magnitude of the net electric field at point P.
5.[1]
Explain why the direction of the electric field is not the same as the direction of the electric potential gradient in this case.
Question 5
SLPaper 2
An electron gun is used to produce a narrow beam of electrons which enters a region of uniform magnetic field. The electrons follow a circular path in this magnetic field.
1.[1]
State the direction of the force acting on an electron when it enters the magnetic field perpendicularly.
2.[1]
Write an equation for the magnetic force acting on a charged particle moving in a magnetic field.
3.[2]
Describe the path taken by the electron in the magnetic field and explain the cause of this motion.
4.[2]
Calculate the speed of an electron accelerated from rest through a potential difference of 4.0 kV.
5.[3]
Determine the radius of the circular path taken by the electron in a magnetic field of 0.30 T.
6.[1]
Suggest why a vacuum is necessary in the tube containing the electron beam.
Question 6
HLPaper 2
A rectangular coil with 120 turns, length and width is pulled at constant velocity into a uniform magnetic field of perpendicular to the plane of the coil. It takes for the entire coil to enter the field.
1.[2]
Calculate the change in magnetic flux through the coil during this interval.
2.[2]
Determine the average emf induced during this time.
3.[2]
Explain how the induced emf would change if the coil entered the magnetic field at an angle.
Question 7
SLPaper 2
The Moon orbits the Earth at an average distance of . The mass of the Earth is and .
1.[1]
State the direction of the gravitational field produced by the Earth.
2.[2]
Calculate the gravitational field strength at the Moon’s orbit due to the Earth.
3.[1]
Explain why the Moon remains in orbit despite this weak field.
Question 8
HLPaper 2
A coil of wire with turns is placed in a region where the magnetic flux through the coil changes uniformly from to in .
1.[1]
State Faraday’s law of electromagnetic induction.
2.[2]
Calculate the magnitude of the average induced emf in the coil.
3.[1]
Explain how Lenz’s law determines the direction of the induced emf.
Question 9
HLPaper 2
A straight conductor of length moves at a speed of perpendicular to a magnetic field of strength .
1.[1]
State the condition under which a moving conductor in a magnetic field induces an emf.
2.[2]
Calculate the induced emf across the ends of the conductor.
3.[1]
Explain what would happen to the induced emf if the conductor moved parallel to the magnetic field.
Question 10
SLPaper 2
An electron is accelerated from rest through a potential difference of and enters a region of uniform magnetic field of strength directed perpendicular to its velocity. Charge of electron , mass .
1.[2]
Calculate the speed of the electron just before it enters the magnetic field.
2.[2]
Determine the radius of its circular path in the magnetic field.
3.[2]
Calculate the frequency of revolution of the electron.
4.[1]
Calculate the number of revolutions the electron completes in .
5.[1]
Describe qualitatively what would happen to the electron’s trajectory if the magnetic field strength were gradually increased.