HESI A2
HESI A2 Physics Practice Test Questions
Question 1 of 5
Which of the following materials has the lowest density?
Correct Answer: B
Rationale: Cork has the lowest density among the given options. Cork is a lightweight material derived from the bark of cork oak trees and is known for its low density, making it float on water. Water, aluminum, and steel have higher densities compared to cork. Water is denser than cork because it has a consistent density of 1 g/cm³. Aluminum and steel are metals with much higher densities due to their atomic structures, making them denser than cork.
Question 2 of 5
Cavitation is a phenomenon observed in fluids when the pressure falls below its:
Correct Answer: D
Rationale: Cavitation is a phenomenon where vapor bubbles form in a fluid due to pressure dropping below the vapor pressure of the liquid. When this occurs, the bubbles collapse, creating intense shock waves. The pressure falling below the vapor pressure is what triggers cavitation, not the boiling point, density, or freezing point of the fluid.
Therefore, the correct answer is 'Vapor pressure,' as it directly relates to the pressure threshold required for cavitation to happen.
Question 3 of 5
When a dielectric material is inserted between the plates of a charged capacitor, what will happen to the capacitance?
Correct Answer: A
Rationale: When a dielectric material is inserted between the plates of a charged capacitor, the capacitance will increase. This is because the presence of a dielectric material reduces the electric field between the plates, allowing more charge to be stored for a given voltage, thus increasing the capacitance.
Choice B is incorrect because adding a dielectric material increases capacitance.
Choice C is incorrect because capacitance changes when a dielectric is added.
Choice D is incorrect because the effect of a dielectric on capacitance is predictable.
Question 4 of 5
Faraday's law of electromagnetic induction states that a changing magnetic field in a conductor induces a/an:
Correct Answer: B
Rationale: Faraday's law of electromagnetic induction states that a changing magnetic field induces an electromotive force in a conductor. This electromotive force is responsible for generating electricity in power plants and various electrical devices. The induced current is a result of the changing magnetic field, not an increase in resistance (choice
A), static electric charge (choice
C), or a decrease in capacitance (choice
D). Hence, the correct answer is B.
Question 5 of 5
When a gas is compressed isothermally, we can say that:
Correct Answer: D
Rationale: When a gas is compressed isothermally, the surroundings perform work on the gas. In this process, since the temperature remains constant (isothermal), the internal energy of the gas does not change.
Therefore, the correct answer is that the surroundings perform work on the gas, and its internal energy decreases.
Choices A, B, and C are incorrect because they incorrectly describe the direction of work and the change in internal energy during an isothermal compression.