Nokea
Which property of a wave remains constant when it crosses a boundary between two different media?
- A. Frequency
- B. Wavelength
- C. Amplitude
- D. Speed
Correct Answer: D
Rationale: When a wave crosses a boundary between two different media, its speed is the property that remains constant. This is due to the principle of conservation of energy. While the frequency and wavelength of a wave may change as it moves from one medium to another, the speed of the wave remains constant. This phenomenon is a result of the wave adjusting its frequency and wavelength to maintain a consistent speed in different media. Therefore, choices A, B, and C are incorrect. Frequency and wavelength may change when a wave moves across media, and amplitude may also be affected by the medium, but the speed of the wave will remain constant.
You may also like to solve these questions
What are isotopes?
- A. Atoms of the same element with different numbers of protons.
- B. Atoms of the same element with different numbers of neutrons.
- C. Atoms of different elements with the same number of protons.
- D. Atoms of different elements with the same number of electrons.
Correct Answer: B
Rationale: Isotopes are atoms of the same element with different numbers of neutrons. While isotopes share the same number of protons, which determines the element, they differ in the number of neutrons. This variance in neutron count results in isotopes having different atomic masses. Choice A is incorrect because isotopes have the same number of protons (same element) but differ in the number of neutrons. Choice C is incorrect as it describes atoms of different elements, not isotopes of the same element. Choice D is also incorrect because isotopes can have different numbers of electrons, but what defines isotopes is the variation in neutron numbers.
Which type of cell has a nucleus but lacks membrane-bound organelles?
- A. Plant cell
- B. Prokaryotic cell
- C. Animal cell
- D. Fungal cell
Correct Answer: B
Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.
What is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy called?
- A. Nuclear fusion
- B. Nuclear fission
- C. Radioactive decay
- D. Chain reaction
Correct Answer: B
Rationale: The correct answer is B: Nuclear fission. Nuclear fission is the process of splitting a heavy nucleus into smaller nuclei, releasing a vast amount of energy. This process is commonly used in nuclear power plants and nuclear weapons. It is a controlled chain reaction that generates energy. Option A, Nuclear fusion, is the process of combining two light nuclei to form a heavier nucleus, releasing energy. This process powers the sun and other stars. Option C, Radioactive decay, is the process by which an unstable atomic nucleus loses energy by emitting radiation. Option D, Chain reaction, is a self-sustaining reaction where the products of one reaction event stimulate further reaction events. While chain reactions can occur in both nuclear fission and fusion, the specific process of splitting a heavy nucleus into smaller ones is known as nuclear fission.
Which of the following is a characteristic phenomenon associated with Cherenkov radiation?
- A. Alpha particle emission
- B. Beta particle emission
- C. Gamma ray emission
- D. Charged particles exceeding the speed of light in a medium
Correct Answer: D
Rationale: Cherenkov radiation is produced when charged particles travel through a medium at speeds greater than the speed of light in that medium. It is not specific to a particular type of particle emission but rather to the speed of the charged particles. This phenomenon results in the emission of a characteristic blue light, which is a visual indicator of charged particles exceeding the speed of light in that medium. Choices A, B, and C are incorrect because Cherenkov radiation is not limited to a specific type of particle emission but is based on the speed of the charged particles relative to the speed of light in the medium.
What is the scientific name for the kneecap?
- A. Patella
- B. Femur
- C. Tibia
- D. Fibula
Correct Answer: A
Rationale: The correct answer is A: Patella. The patella is the scientific term for the kneecap, a small, flat, triangular bone situated in front of the knee joint. The femur, tibia, and fibula are also bones in the leg, but they are not synonymous with the kneecap. The femur is the thigh bone, the tibia is the shin bone, and the fibula is the outer lower leg bone. Therefore, the correct term for the kneecap specifically is the patella.