Nokea
What does Coulomb's law relate to?
- A. electrostatic interaction
- B. rigid body motion
- C. heat conduction
- D. universal gravitation
Correct Answer: A
Rationale: Coulomb's law is a fundamental principle in physics that deals with the electrostatic interaction between charged particles. It states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. This law is crucial in understanding and predicting the behavior of electrically charged objects. Choices B, C, and D are incorrect because Coulomb's law specifically focuses on electrostatic interactions between charges, not rigid body motion, heat conduction, or universal gravitation.
You may also like to solve these questions
Two objects attract each other with a gravitational force of 12 units. If the distance between them is halved, what is the new force of attraction between the two objects?
- A. 3 units
- B. 6 units
- C. 24 units
- D. 48 units
Correct Answer: C
Rationale: The gravitational force between two objects is inversely proportional to the square of the distance between them. When the distance is halved, the new force of attraction will be 12 units x (1/(0.5)^2) = 12 units x 4 = 24 units. Therefore, the correct answer is C. Choice A and B are incorrect as they do not consider the inverse square law of gravitational force. Choice D is incorrect as reducing the distance between the objects does not lead to a squared increase in force.
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.
If a 5-kg ball is moving at 5 m/s, what is its momentum?
- A. 10 kgâ‹…m/s
- B. 16.2 km/h
- C. 24.75 kgâ‹…m/s
- D. 25 kgâ‹…m/s
Correct Answer: D
Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the mass of the ball is 5 kg and its velocity is 5 m/s. Therefore, the momentum of the ball is 5 kg 5 m/s = 25 kgâ‹…m/s. Choice A (10 kgâ‹…m/s) is incorrect as it does not account for both mass and velocity. Choice B (16.2 km/h) is incorrect as it provides a speed in a different unit without considering mass. Choice C (24.75 kgâ‹…m/s) is incorrect as it does not correctly calculate the momentum based on the given mass and velocity.
What is the phenomenon by which light bends as it passes through a prism known as?
- A. Reflection
- B. Electrical conduction
- C. Diffraction
- D. Refraction
Correct Answer: D
Rationale: Refraction is the phenomenon by which light bends as it passes through a prism or any other medium boundary. When light transitions from one medium to another, such as air to glass in the case of a prism, it changes speed and direction due to the change in the medium's refractive index. This change in speed causes the light to bend. Reflection, on the other hand, is the bouncing back of light when it hits a surface. Diffraction refers to the bending of light around obstacles or through narrow openings. Electrical conduction involves the movement of electrically charged particles through a conductor, which is unrelated to the bending of light.
A 110-volt appliance draws 0 amperes. How many watts of power does it require?
- A. 0 watts
- B. 108 watts
- C. 112 watts
- D. 220 watts
Correct Answer: A
Rationale: When a 110-volt appliance draws 0 amperes, it means that the power consumption is zero as well. The formula to calculate power is P = V x I, where P is power in watts, V is voltage in volts, and I is current in amperes. Since the current is 0 amperes, the power required by the appliance is also 0 watts. Therefore, the correct answer is 0 watts. Choice B, 108 watts, is incorrect because there is no current drawn. Choice C, 112 watts, and choice D, 220 watts, are incorrect as well since the appliance is not consuming any power when drawing 0 amperes.