HESI Exams Quizlet Physics

Correct Answer: A

Rationale: To find the current flowing through the flashlight, use Ohm's Law: Current (I) = Voltage (V) / Resistance (R). Given V=3V and R=60Ω, I = 3V / 60Ω = 0.05 amp (A). This is the correct answer. Choice B, 0.5 amp, is incorrect as it does not match the calculated value. Choice C and D, 1.8 amp and 18 amp respectively, are also incorrect as they are significantly higher than the calculated current value and would require a much higher voltage source.

Correct Answer: C

Rationale: Potential energy increases as particles approach each other because the distance between them decreases, leading to an increase in repulsive forces due to the close proximity of the particles. This causes the potential energy to rise as the particles try to move away from each other to reduce the repulsive forces. Attractive forces do not increase in this scenario, and in fact, they may decrease due to the particles being closer together. Repulsive forces increase as the particles get closer, not decrease. Therefore, the correct answer is C.

Correct Answer: B

Rationale: The correct answer is B: Decrease. When one side of the U-tube manometer is connected to a pressurized system, the pressure on that side will be higher, causing the fluid level to decrease due to the increase in pressure. This is because the pressure difference between the two sides of the manometer causes the fluid to move towards the side with higher pressure. Choice A is incorrect because the fluid level will not remain the same in response to the pressure change. Choice C is incorrect as the fluid level will decrease, not increase. Choice D is incorrect as the type of fluid used does not affect how the fluid level changes in response to pressure.

Correct Answer: B

Rationale: The correct answer is B (15.625 cm). To calculate the image height using mirror formula (1/f = 1/v + 1/u), first find the object distance (u) which is -20 cm (since object is placed on the same side as focal point, it is negative). Then, solve for image distance (v) by substituting u and f values. Next, use magnification formula (m = -v/u) to find the magnification factor. Finally, multiply the object height by the magnification factor to get the image height, which is 15.625 cm. Choice A (30.5 cm) is incorrect as it is double the correct answer. Choice C (-15 cm) and choice D (-30.5 cm) are incorrect as the negative sign indicates an inverted image, but in this case, the image is upright.

Correct Answer: B

Rationale: To find the period of a wave, we use the formula: Period = 1 / Frequency. Given the frequency of 80 vibrations per second, we calculate the period as 1 / 80 = 0.025 seconds. Therefore, choice B (0.025 s) is the correct answer. Choices A, C, and D are incorrect as they do not correctly represent the period calculation based on the given frequency. Choice A (0.0125 s) is half of the correct period, choice C (0.125 s) is ten times greater, and choice D (0.25 s) is incorrect as well.