MEDIUM
9th CBSE
IMPORTANT
Earn 100

State and explain the law of conservation of energy with an example.

Important Questions on Work and Energy

MEDIUM
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 32
Explain how, the total energy of a swinging pendulum at any instant of time remains conserved. Illustrate your answer with the help of a labelled diagram.
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 33
What is the meaning of the symbol kWh? What quantity does it represent?
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 33
How much electric energy in kWh is consumed by an electrical appliance of 1000 watts when it is switched on for 60 minutes?
MEDIUM
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 34
Derive the relation between commercial unit of energy (kWh) and SI unit of energy (joule).
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 34
A certain household consumes 650 units of electricity in a month. How much is this electricity in joules?
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 35
Define power. Give the SI unit of power.
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Long Answer Type Questions>Q 35
A boy weighing 40 kg carries a box weighing 20 kg to the top of a building 15 m high in 25 s. Calculate the power, (g=10 m/s2)
EASY
9th CBSE
IMPORTANT
Science for Ninth Class Part 1 Physics>Chapter 4 - Work and Energy>Multiple Choice Questions (MCQs)>Q 36
When an object falls freely towards the earth, then its total energy: