Physics Class9

Does work done depend upon the velocity of the body?

• Yes

• No

What will cause greater increase in kinetic energy of a body?

• Increase in mass

• Increase in velocity

• Increase in displacement

• Increase in force

What is the SI unit of work done, power, and force respectively?

• Joule, Metre, Watt

• Metre, Watt, Newton

• Joule, Watt, Newton

• Newton, Metre, Joule

Find the energy in kWh consumed in 10 hours by a machine of power 500 W.

• 5000Wh

• 5000kWh

• 5kWh

• 5Wh

When a book is lifted from a table, against which force work is done ?

• Muscular Force

• Gravitational Force

• Magnetic Force

• Electrostatic Force

What is the work done when force in the situation shown above ?

• Positive

• Negative

• Zero

A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done due to gravity ?

(Write only magnitude in number)

A lamp consumes 180 kJ of electrical energy in 5 hrs. What is its power ?

• 18 Watt

• 36 Watt

• 10 Watt

• 90 Watt

A body performs no work. Does it imply that the body possesses energy ?

• Never

• Always

• May be

Who verified experimentally the law of conservation of energy?

• John Dalton

• James Prescott Joule

• Blaise Pascal

• Galileo Galilei

• Isaac Newton