Free Work and Energy MCQs with Answers
748 Work and Energy MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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Read the Work and Energy notesFree MDCAT chapter notes with key terms748 questions · page 14 of 38
- A. -225 j
- B. -240 j
- C. -245 j
- D. -250 j
Explanation: Change in position vector:The particle moves from the origin (0, 0) to the point (12m, 5m).The change in position vector (Δr) is: Δr =…
Correct answer: -240 j- A. Rotation of earth
- B. Mass of body
- C. Radius of earth
- D. Mass of earth
Explanation: The formula for escape velocity (v) is:v = √(2GM/R)where:G is the gravitational constantM is the mass of EarthR is the radius of EarthAs…
Correct answer: Radius of earth- A. Vα 3P/m
- B. V^2 α 3P/m
- C. V^3α 3P/m
- D. Vα (3P/m)^2
Explanation: Here's how we can find the relationship between the velocity (V), mass (m), power (P), and distance (x):1.
Correct answer: V^3α 3P/m- A. 1 unit
- B. 9 units
- C. 13 units
- D. 60 units
Explanation: The work done by a force is the dot product of the force and the displacement.1.
Correct answer: 9 units- A. 3m
- B. 6m
- C. 9m
- D. 12m
Explanation: When the ball is dropped, its initial kinetic energy (KE) is 0 because it's at rest.
Correct answer: 9m- A. 9.8
- B. 1.96
- C. 4.9
- D. none
Explanation: Here's how we can find the acceleration due to gravity (g) on the moon's surface1.
Correct answer: 1.96- A. P2t2/m
- B. P2t2/2m
- C. P2t2/3m
- D. P t/2m
Explanation: Here's how we can find the kinetic energy of the particle:1. Work done by the force:The work done by the force (W) is given by the…
Correct answer: P2t2/2m- A. 9.75
- B. 11.2
- C. 2.3
- D. 15.6
Explanation: Escape velocity is the minimum velocity an object needs to break free from the gravitational attraction of a massive body, without further…
Correct answer: 11.2- A. Double
- B. 4 times
- C. Half
- D. ¼ time
Explanation: The work done (W) is given by the formula:W= F.dWhere F is the force appliedd is the displacement in the direction of forceNow, if both…
Correct answer: 4 times- A. 3.2kw
- B. 5kw
- C. 32kw
- D. 50kw
Explanation: The electrical power can be found using the formula:Pelectrical= W/ ΔtWhere W is the work doneΔt is the time taken.We may write:W=…
Correct answer: 32kw- A. 0
- B. 30
- C. 60
- D. 90
Explanation: Correct. The work done is given by \( W = F \cdot d \cdot \cos(\theta) \), where \( \theta \) is the angle between the force and the…
Correct answer: 30- A. Rotation of earth
- B. Mass of body
- C. Radius of body
- D. Mass of Earth
Explanation: The escape velocity from a celestial body, such as Earth, depends on the mass of the body.
Correct answer: Mass of Earth- A. One fourth
- B. Double
- C. Four times
- D. Half
Explanation: Kinetic energy is proportional to the square of velocity. When the velocity becomes half, the kinetic energy becomes one-fourth of its…
Correct answer: Half- A. Converted into kinetic energy
- B. Wasted in air
- C. Converted into sound
- D. Consumed in breaking of glass
Explanation: Energy Transformation: The potential energy of the glass is indeed initially converted to kinetic energy as it falls.
Correct answer: Consumed in breaking of glass- A. watt
- B. Ampere
- C. Newton
- D. Joules
Explanation: Power is the rate at which work is done. It is defined as the work done per unit time.Mathematical Form:Power (P) = Work Done (W) / Time…
Correct answer: watt- A. 25/16 K
- B. 23/34 K
- C. 12/45 K
- D. 34/58 K
Explanation: The kinetic energy of a body is given by:K.E = 1/2 * m * v^2Where:K.E is the kinetic energym is the mass of the bodyv is the velocity of…
Correct answer: 25/16 K- A. 0
- B. 90
- C. 180
- D. 4
Explanation: Work done by a force is given by the dot product of force and displacement:W = F .
Correct answer: 0278. Dimensions of U are:
- A. [ML^-1 T^-1]
- B. [ML^2 T^-2]
- C. [ML^1 T^-1]
- D. [ML^1 T^-2]
Explanation: U represents potential energy, which is defined as the energy possessed by an object due to its position or configuration.The formula for…
Correct answer: [ML^2 T^-2]- A. Electric force
- B. Gravitational force
- C. Tension in string
- D. Elastic spring force
Explanation: A conservative force is a force that does not depend on the path taken by an object, only on its initial and final positions.
Correct answer: Tension in string280. What is the power of a body if 1N force is acted upon a body have a constant velocity of 10ms^-1?
- A. 0
- B. 30
- C. 0.5
- D. 10
Explanation: Power is the rate at which work is done. It is defined as the work done per unit time.Power (P) = Work Done (W) / Time (t)Work done (W) =…
Correct answer: 10