Nursing Elites

1. A 120-volt heat lamp draws 25 amps of current. What is the lamp’s resistance?

• A. 96 ohms
• B. 104 ohms
• C. 150 ohms
• D. 4.8 ohms

Correct answer: D

Rationale: To find the resistance of the lamp, we use Ohm’s Law, which states that resistance (R) is equal to voltage (V) divided by current (I), expressed as: R = V / I. Given that the voltage (V) is 120 volts and the current (I) is 25 amps, we substitute these values into the formula: R = 120 V / 25 A = 4.8 ohms. Therefore, the resistance of the lamp is 4.8 ohms. Choice A, 96 ohms, is incorrect as it is not the result of the correct calculation. Choice B, 104 ohms, is incorrect as it does not match the calculated resistance. Choice C, 150 ohms, is incorrect as it is not the correct resistance value obtained through the calculation.

2. 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.

3. Two objects attract each other with a gravitational force of 12 units. If you double the distance between the objects, what is the new force of attraction between the two?

• A. 3 units
• B. 6 units
• C. 24 units
• D. 48 units

Correct answer: A

Rationale: The gravitational force between two objects is inversely proportional to the square of the distance between them. If the distance is doubled, the force will be reduced to 1/4 of the original force. Therefore, the new force of attraction between the two objects will be 12 units / 4 = 3 units. Choice A is correct because doubling the distance reduces the force to 1/4 of the original value. Choices B, C, and D are incorrect as they do not consider the inverse square relationship between distance and gravitational force.

4. Certain non-Newtonian fluids exhibit shear thickening behavior. In this case, the fluid's viscosity:

• A. Remains constant with increasing shear rate
• B. Decreases with increasing shear rate (shear thinning)
• C. Increases with increasing shear rate
• D. Depends solely on the applied pressure

Correct answer: C

Rationale: When a non-Newtonian fluid exhibits shear thickening behavior, its viscosity increases with increasing shear rate. This means that as more force is applied to the fluid, its resistance to flow also increases, resulting in a higher viscosity. This phenomenon is opposite to shear thinning, where viscosity decreases with increasing shear rate. Therefore, in the case of shear thickening behavior, the correct answer is that the fluid's viscosity increases with increasing shear rate. Choices A, B, and D are incorrect because shear thickening behavior specifically involves an increase in viscosity with increasing shear rate, not remaining constant, decreasing, or depending on applied pressure.

5. When a car is driven for a long time, the pressure of air in the tires increases. This is best explained by which of the following gas laws?

• A. Boyle's law
• B. Charles' law
• C. Gay-Lussac's law
• D. Dalton's law

Correct answer: C

Rationale: Gay-Lussac's law, also known as the law of pressure-temperature, states that the pressure of a gas is directly proportional to its absolute temperature when the volume is constant. As a car is driven for a long time, the tires heat up due to friction and increased air pressure inside the tires. This results in an increase in temperature, causing the pressure of the air inside the tires to increase according to Gay-Lussac's law. Choices A, B, and D are incorrect. Boyle's law relates pressure and volume, Charles' law relates volume and temperature, and Dalton's law deals with the partial pressures of gases in a mixture.

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