Nokea
What is the unit of measurement for power?
- A. Joule (J)
- B. Newton (N)
- C. Watt (W)
- D. Kilogram-meter (kg·m)
Correct Answer: C
Rationale: Power is the rate at which work is done or energy is transferred. The unit of measurement for power is the watt (W), named after James Watt, the inventor of the steam engine. The watt is defined as one joule per second, where a joule (J) is the unit of energy. Choice A, Joule (J), is incorrect because a joule is a unit of energy, not power. Choice B, Newton (N), is incorrect as a Newton is a unit of force, not power. Choice D, Kilogram-meter (kg·m), is incorrect as it represents a unit of torque, not power. Therefore, the correct answer is C: Watt (W).
You may also like to solve these questions
Which of the following is used to record the measurable electrical activity of the brain?
- A. CAT scan
- B. MRI scan
- C. Electroencephalogram (EEG)
- D. X-ray
Correct Answer: C
Rationale: The correct answer is an Electroencephalogram (EEG). An EEG is specifically designed to record the measurable electrical activity of the brain. It does so by using small, flat metal discs (electrodes) attached to the scalp to detect brain activity. This test is crucial in diagnosing various conditions like seizures, epilepsy, head injuries, dizziness, headaches, and brain tumors. The other options, CAT scan, MRI scan, and X-ray, are imaging techniques that do not directly measure the brain's electrical activity. CAT scan and MRI scan provide detailed images of the brain's structure, while X-ray is more suited for visualizing bone structures or dense tissues.
Which term refers to the relaxation of the heart muscle?
- A. Diastole
- B. Systole
- C. Asystole
- D. Cardiastole
Correct Answer: A
Rationale: The correct answer is A: Diastole. Diastole is the phase of the heartbeat when the heart muscle relaxes, allowing the chambers to fill with blood. Systole, on the other hand, refers to the contraction phase of the heart when it pumps blood out. Asystole is the absence of heart contractions, often referred to as cardiac arrest. Cardiastole is not a recognized medical term in relation to heart muscle relaxation, making it an incorrect choice.
What is molarity a measure of in a solution?
- A. Volume of the solvent
- B. Amount of solute
- C. Concentration of solute
- D. Temperature of the solution
Correct Answer: C
Rationale: Molarity is a measure of the concentration of a solute in a solution. It is defined as the number of moles of solute per liter of solution. Molarity is not a measure of the volume of the solvent (choice A), the amount of solute (choice B), or the temperature of the solution (choice D). Therefore, the correct answer is the concentration of solute (choice C) as molarity specifically quantifies the solute concentration in a solution.
Which factor affects the gravitational potential energy of an object the most?
- A. The mass of the object
- B. The distance from the ground
- C. The gravitational force
- D. The shape of the object
Correct Answer: B
Rationale: Gravitational potential energy is directly proportional to the height or distance from the ground. As the object is raised higher, its gravitational potential energy increases. While the mass of the object influences gravitational potential energy, the distance from the ground has a more significant impact on it. The gravitational force does not directly affect the gravitational potential energy; it is the force that causes the potential energy to change with height. The shape of the object also does not determine gravitational potential energy, as it is primarily determined by the object's position in a gravitational field.
When sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl), the resulting product is:
- A. Hydrogen gas and sodium chloride (NaCl)
- B. Chlorine gas and sodium oxide (Na2O)
- C. Sodium metal (Na) and water (H2O)
- D. No reaction occurs.
Correct Answer: A
Rationale: When sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl), a neutralization reaction occurs. The products of this reaction are water (H2O) and a salt, which is sodium chloride (NaCl). The chemical equation for this reaction is: NaOH + HCl -> NaCl + H2O. Choice B is incorrect because chlorine gas and sodium oxide are not the products of this reaction. Choice C is incorrect as sodium metal and water are not the products formed in this neutralization reaction. Choice D is incorrect because a reaction does occur between NaOH and HCl, resulting in the formation of NaCl and H2O. Therefore, the correct answer is A: Hydrogen gas and sodium chloride (NaCl).