Work and Energy Quiz - CBSE Class 9 Science
Free practice quiz: Work and Energy (CBSE Class 9 Science). 18 multiple-choice questions with answers and explanations. Play online, no sign-up needed.
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What is work done when a force moves an object 1 meter in the direction of the force?
- 1 Joule
- 2 Joules
- 0.5 Joules
- 3 Joules
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Answer: A. 1 Joule
Work is defined as the product of force and displacement in the direction of the force. Here, if a force of 1 Newton moves an object 1 meter, the work done is 1 Joule (Work = Force x Displacement = 1N x 1m).
What is kinetic energy?
- Energy stored in an object
- Energy due to motion
- Energy due to position
- None of the above
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Answer: B. Energy due to motion
Kinetic energy is defined as the energy an object possesses due to its motion, expressed as KE = 1/2 mv².
If a system converts all its potential energy into kinetic energy, what can be said about the total energy?
- It is lost
- It is conserved
- It increases
- It decreases
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Answer: B. It is conserved
According to the law of conservation of energy, energy in a closed system remains constant. Potential energy converted to kinetic energy means total energy is conserved.
An object of mass m is lifted to a height h. Which of the following expressions gives its potential energy?
- mgh
- 1/2 mv²
- mgh/2
- gh
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Answer: A. mgh
The potential energy of an object lifted to a height h is given by PE = mgh, where m is mass and g is the acceleration due to gravity.
In a closed system, if energy is converted from one form to another, what can be said about the total energy?
- It increases
- It decreases
- It is conserved
- It changes unpredictably
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Answer: C. It is conserved
In a closed system, energy can change forms (e.g., potential to kinetic) but the total energy remains constant, demonstrating conservation of energy.