Work is the transfer of energy when a force acts on an object over a distance. Energy is the capacity to perform work, existing in various forms such as kinetic, potential, and thermal, crucial in physical processes.
Physics Class 11 Chapter 4 Notes
The conservation of energy is written as: Total energy = K.E + P.E
Energy can be transformed from one kind into another but the total amount of energy: remain same
The escape velocity of the earth is: greater than moon
Escape velocity of a body depends upon: mass of planet
A body of mass 5kg has P.E 100J. Its height from the ground is: 2m
The total amount of energy at any point: remain constant
Which of the following is mechanical energy: P.E, K.E
By neglecting the air friction, then relation for free falling body is: loss in P.E = gain in K.E
The relation P.E=mgh is true only near the surface of earth where the gravitational field is: constant
The relation P.E=mgh is the work done by the gravitational force is true only: near the surface of earth
The energy stored in the catapult when it pulls is: elastic P.E
All the food a person eat in one day has about the same energy as: 1/3 liter of petrol
If the speed of body increased by 3 times, then its K. E is increased by: 9 times
The velocity which is given to a body to enable it to reach at infinite distance from earth is called: escape velocity
The energy stored in a dam is: gravitational P.E
In explosion which energy is changed into sound energy: chemical energy
A brick of mass 2kg falls from height 10m. it velocity when its height is 5m: 10ms–1
When two protons are brought close to each other then their: P.E increases
A body at rest may has: potential energy
In a resistive medium, the loss of P.E of any body is: equal to gain in K.E plus the work done against friction
The energy stored in the spring of watch is: elastic P.E
Particles of different masses have same momentum. Which of them has the highest K.E which has: least mass
If a body raised up from the earth‟s surface, the work done changes the: gravitational P.E
P.E of a body increases this means work done by gravity is: negative
If a spring is compressed, the work done on it equals the: increase in elastic P.E
When we raise the body above the surface of the earth its P.E within the gravitational field: increases
A body of mass five kg has P.E 98J. Its height from the ground is: 2m
Basic forms of mechanical energy are: 2
If velocity of a body is doubled and its mass is also doubled then K.E of the body becomes: eight times
The work energy principle is valid for: Change in P.E
Consumption of Energy by a 60 Watt Electric Bulb in 2 seconds is: 120 J
One kilo watt hour is equal to: 3.6 MJ
Energy stored in spring is: elastic P.E
The K.E of bullet of mass 500 gm moving at a speed of 200 ms-1 is: 10,000J
The energy needed to lift a mass of 5000g to height of 1m is: 50 J
A stone is thrown up from the surface of earth when it reaches at maximum height, its K.E. is equal to: Zero
A body of mass 1.0 kg drops form the top of a tower of height 50m, what will be its K.E, 10 m below the top: 98 J
__ is non-conservative force: frictional force
If the velocity of an object is double then its K.E becomes: four times
The energy possessed by a body due to its motion is called: K.E
Power is one kilowatt if work is done at the rate of: 1000Js–1
One kilo watt hour is the amount of work done in: one hour
The average power and instantaneous power becomes equal if the work is done at: uniform rate
The power needed to lift a mass of 5000g to height of 1m in 2sec is: 24.5watt
If an agent consumes a power of 1kilo-watt in one hour, the work done is: one kilowatt-hour
1 MWh is equal to __ joule: 3.6 × 109
Kilo watt is unit of: energy
3 joules of work is done in 3 seconds, then power is: 1 watt
1 Kilowatt hour is a unit of: energy
Slope of work time graph is equal to: power
The field or space around the earth in which the gravitational forces acts on a body is called: gravitational field
If a body of weight w is lifted through a height „h‟ from ground, then the work done by the gravity will be: –wh
The total work done in a closed path in gravitational field is: zero
In conservative field the work done is independent of: path followed by the body
Which one is the bigger unit of work: kilo watt hour
A field in which work done in moving a body in a closed path is zero is called: conservative field
A force of 10N acts on the body and body moves 10m distance perpendicular to it. Work done by the force on the body is: zero
Which one is a conservative force: friction
Work done by a variable force for the first interval is: F1 cosθ1 Δd1
Force of gravity varies as the __ square of distance from the Earth‟s center: inverse
When force acting on body is variable then work is determined by dividing: displacement into intervals
Work done by a variable force making angles at different points with displacement in moving the particle from one point to another is equal to the area under the curve of: F cos θ versus d
When rocket moves away from the Earth, then work is done: against force of gravity
Work done by a person holds a bag of groceries while standing still is: zero
Area under force displacement curve gives: work done
The work is said to be 1 J when the force of 1N moves the body in its direction through a distance of: 1m
A body of mass 4kg is moving with a velocity of 4m/sec. How much force is required to stop the body with in a distance of one meter: 32N
1erg =: 10–7 J
The unit of work in CGS system is: erg
The work done would be zero, if the angle between force and displacement is: 90o
If θ > 900 work is said to be: negative
Work is a: scalar quantity
1 Joule =: N m
When force and displacement are in opposite direction, then the work done is taken as: Negative
If θ < 900 work is said to be: positive
The component of force in the direction of the displacement „d‟ is: F cosθ
Dimension of work is same that of: torque
At which angle between force and displacement work done by force is half than its maximum: 60o
Work done is negative if θ is: 180°
Scalar product of force and velocity is: power
Work has dimensions as that of: torque
Work done is maximum when the angle between force and displacement is: 0°
Work is the dot product of: force and displacement
Important : Review all previous years’ 11 Class Past Papers for comprehensive practice and better exam preparation.