A Level Physics Practice Exam

Which interactions do hadrons and leptons both experience?

1. Gravitational interaction and electromagnetic interaction

2. Weak interaction and strong interaction

3. Weak interaction and, if charged, electromagnetic interaction

4. Electromagnetic interaction and gravitational interaction

The correct answer is: Weak interaction and, if charged, electromagnetic interaction

Hadrons and leptons both share the weak interaction as a fundamental force at play in their interactions. The weak interaction, also known as the weak nuclear force, is responsible for processes such as beta decay in hadrons and various interactions involving neutrinos and charged leptons. In addition, charged leptons—like electrons—experience the electromagnetic interaction because they possess an electric charge. Hadrons, being made up of quarks, also experience the electromagnetic interaction if they have a net charge. However, it is important to note that neutral hadrons, such as neutrons, do not participate in electromagnetic interactions. Thus, the answer reflects that both hadrons (which can carry charge) and leptons (if they are charged) are involved in the weak interaction and additionally experience the electromagnetic interaction when considering the charged leptons. The mention of gravitational interaction does not apply in this context, as it is negligible in particle interactions compared to the fundamental forces mentioned.