# Worksheet: Identifying Particles in Detectors

In this worksheet, we will practice determining the charge and mass of particles from the paths that they follow through particle detectors.

Q1:

An up quark has a mass of 2,300 keV/c2. What is the mass of an up quark in kilograms? Give your answer to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q2:

What is kg in mega-electron volts per speed of light squared (MeV/c2)? Give your answer to 3 significant figures.

Q3:

An electron has a mass of kg. What is the mass of an electron in kilo-electron volts per speed of light squared (keV/c2)? Give your answer to 3 significant figures.

Q4:

A muon has a mass of 106 MeV/c2. What is the minimum energy of a photon that can produce a muon and an antimuon via pair production? Give your answer in mega-electron volts.

Q5:

A tauon has a mass of 1,780 MeV/c2 and a muon has a mass of 106 MeV/c2. What is the ratio of the mass of a tauon to the mass of a muon? Give your answer to 3 significant figures.

Q6:

An electron has a mass of 511 keV/c2. What would the energy of a photon that was produced from the annihilation of an electron and a positron be? Assume that the kinetic energy of the two particles is negligible. Give your answer in kilo-electron volts.

Q7:

What is 15.0 eV/c2 in kilograms? Give your answer to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q8:

A muon moves through a uniform magnetic field with a field strength of 0.100 T. It has a constant speed of m/s. What is the radius of the circular path that it follows? Take the muon to have a mass of kg and a charge of C. Give your answer to 3 significant figures.

Q9:

What magnetic field strength of a uniform magnetic field is required to make an electron moving at a speed of m/s follow a circular path with a radius of 10.0 cm? An electron has a charge of C and a mass of kg. Give your answer in tesla to 3 significant figures.

• A T
• B T
• C 117 T
• D T
• E T

Q10:

A charged particle moves through a uniform magnetic field in a bubble chamber. It moves along a circular path with a radius of 10.0 cm. Its speed is and its mass is kg. The strength of the magnetic field is 0.280 T. What is the charge of the particle? Give your answer in coulombs to 3 significant figures.

• A C
• B C
• C C
• D C
• E C

Q11:

The diagram shows a charged particle moving through a uniform magnetic field. The particle moves along a circular path. Which of , , , and shows the direction of the force experienced by the charged particle due to the magnetic field?

• A
• B
• C
• D

Q12:

A charged particle moves through a uniform magnetic field in a bubble chamber. It moves along a circular path with a radius of 4.44 mm. Its speed is m/s and its charge is C. The strength of the magnetic field is 0.210 T. What is the mass of the particle? Give your answer in kilograms to 3 significant figures.

• A kg
• B kg
• C kg
• D kg
• E kg

Q13:

A charged particle moves through a uniform magnetic field. It moves along a circular path with a radius of 0.0200 m. Its speed is m/s. The strength of the magnetic field is 0.200 T. What is the charge to mass ratio of the particle? Give your answer in C/kg to 3 significant figures.

• A C/kg
• B C/kg
• C C/kg
• D C/kg
• E C/kg

Q14:

A particle with a mass of is observed in a bubble chamber. The magnetic field inside the bubble chamber is uniform and has a strength of 0.340 T. The particle moves along a circular path with a radius of 31.3 cm at a speed of m/s. What is the magnitude of the relative charge of the particle?

Q15:

The diagram shows a charged particle moving through a uniform magnetic field. The particle moves along a circular path.

Which of , , , and shows the direction of the instantaneous velocity of the charged particle?

• A
• B
• C
• D

Q16:

A particle moves through a uniform magnetic field of strength 0.15 T. The particle moves in a straight line at a speed of 250 km/s. What is the relative charge of the particle?

Q17:

Which of the following is the correct formula for the force experienced by a particle with electric charge moving through a uniform magnetic field of strength at a speed ?

• A
• B
• C
• D
• E

Q18:

A charged particle moving in a magnetic field experiences a force in a direction the direction of the instantaneous velocity of the particle.

• Aperpendicular to
• Bequal to
• Cin the opposite direction to
• Dparallel to

Q19:

What is kg in ? Give your answer to 3 significant figures.

Q20:

A charged particle passes through a uniform magnetic field in a bubble chamber. It decays to particle , which is also a charged particle, and a number of neutral particles, which cannot be seen in the bubble chamber.

If particle initially has the same speed as particle , which particle has the greatest charge-to-mass ratio?

• A
• B

Q21:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber.

Both particles have the same initial velocity. If particle P is an electron, what is particle R?

• AA neutron
• BA positron
• CA muon
• DA photon
• EA meson

Q22:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber. Both particles have the same mass and initial velocity. If particle has an electric charge of , what is the electric charge of particle ?

• A0
• B
• C
• D
• E

Q23:

The diagram shows the paths of two particles in a uniform magnetic field in a bubble chamber.

Particle has a charge of and particle has a charge of . Both particles have the same initial speed. Which particle has the greater mass?

• A
• B
• CBoth have equal masses.

Q24:

The table shows the charge-to-mass ratio of three mesons.

 Particle Charge-to-Mass Ratio (C/kg) 𝜋  Κ  𝐷  6 . 4 3 × 1 0  1 . 8 2 × 1 0  4 . 8 0 × 1 0 

A particle moves through a uniform magnetic field of strength 0.01 T along a circular path with a radius of 0.625 m at a speed of 300 km/s. Which of the particles listed in the table could be that particle?

• A
• B
• C