HESI A2 Physics Practice Test

HESI A2 Physics Practice Test Related

Review HESI A2 Physics Practice Test related questions and content

Which conclusion can be drawn from Ohm's law?

  • A. Voltage and current are inversely proportional when resistance is constant.
  • B. The ratio of the potential difference between the ends of a conductor to current is a constant, R.
  • C. Voltage is the amount of charge that passes through a point per second.
  • D. Power (P) can be calculated by multiplying current (I) by voltage (V).
Correct Answer: B

Rationale: Ohm's law states that the ratio of the potential difference (voltage) between the ends of a conductor to the current flowing through it is a constant. Mathematically, this is represented as V = I x R, where V is voltage, I is current, and R is the constant resistance. Therefore, the correct conclusion that can be drawn from Ohm's law is that the ratio of the potential difference between the ends of a conductor to current is a constant, denoted as R. This relationship is fundamental to understanding the behavior of electrical circuits and the effect of resistance on voltage and current. Choice A is incorrect because Ohm's law actually states that voltage and current are directly proportional when resistance is constant. Choice C is incorrect because voltage is not the amount of charge that passes through a point per second; rather, it is the electric potential energy per unit charge. Choice D is incorrect because although power (P) can be calculated by multiplying current (I) by voltage (V), this is not a conclusion directly drawn from Ohm's law.

You may also like to solve these questions

When calculating an object's acceleration, what must you do?

  • A. Divide the change in time by the velocity.
  • B. Multiply the velocity by the time.
  • C. Find the difference between the time and velocity.
  • D. Divide the change in velocity by the change in time.
Correct Answer: D

Rationale: When calculating an object's acceleration, you must divide the change in velocity by the change in time. Acceleration is defined as the rate of change of velocity with respect to time. By determining the ratio of the change in velocity to the change in time, you can ascertain how quickly the velocity of an object is changing, thereby finding its acceleration. Choice A is incorrect because acceleration is not calculated by dividing time by velocity. Choice B is incorrect as it describes multiplying velocity by time, which does not yield acceleration. Choice C is incorrect as finding the difference between time and velocity is not a method to calculate acceleration.

When a dielectric material is inserted between the plates of a charged capacitor, what will happen to the capacitance?

  • A. Increase
  • B. Decrease
  • C. Remain the same
  • D. Become unpredictable
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.

If the force acting on an object is doubled, how does its acceleration change?

  • A. It remains the same.
  • B. It is halved.
  • C. It is doubled.
  • D. It is eliminated.
Correct Answer: C

Rationale: According to Newton's second law of motion, the acceleration of an object is directly proportional to the force acting on it. Therefore, if the force acting on an object is doubled, its acceleration will also double. This relationship is expressed by the equation F = ma, where F is the force, m is the mass of the object, and a is the acceleration. When the force (F) is doubled, the acceleration (a) will also double, assuming the mass remains constant. Choice A is incorrect because acceleration changes with a change in force. Choice B is incorrect because acceleration and force are directly proportional. Choice D is incorrect because increasing the force acting on an object does not eliminate its acceleration; instead, it results in an increase in acceleration, as per Newton's second law.

Fluids can be categorized based on their shear stress-strain rate relationship. An ideal fluid exhibits:

  • A. Zero shear stress at any strain rate
  • B. Linear relationship between shear stress and strain rate (Newtonian)
  • C. Non-linear relationship between shear stress and strain rate (Non-Newtonian)
  • D. High dependence of viscosity on temperature
Correct Answer: A

Rationale: An ideal fluid, often referred to as an inviscid fluid, is a theoretical concept used in fluid mechanics to simplify calculations. It is characterized by having zero shear stress at any strain rate. In reality, such fluids do not exist, but they serve as a useful starting point for understanding fluid behavior in idealized situations. Choice B is incorrect because a linear relationship between shear stress and strain rate defines a Newtonian fluid, not an ideal fluid. Choice C is incorrect because a non-linear relationship between shear stress and strain rate characterizes Non-Newtonian fluids, not ideal fluids. Choice D is incorrect because the high dependence of viscosity on temperature is a characteristic seen in real fluids and does not define an ideal fluid.

What is the mathematical expression for work (W)?

  • A. W = F / d
  • B. W = F x d
  • C. W = d / F
  • D. W = F^2 x d
Correct Answer: B

Rationale: The correct formula for work (W) is given by the equation W = F x d, where F represents force and d represents the displacement in the direction of the force. Work is calculated by multiplying the force applied by the distance over which the force is applied. Choice A (W = F / d) is incorrect as work is not calculated by dividing force by distance. Choice C (W = d / F) is incorrect because work is not calculated by dividing distance by force. Choice D (W = F^2 x d) is incorrect as work is not calculated by squaring the force and then multiplying by distance.

Copyright © 2025 Nokea. All rights reserved.