Energy and It's Sources

Q.

State the first law of thermodynamics for isochoric process.

Q.

What is an ideal fuel? Give examples.

Q. energy is converted to energy in a thermal power plant.

1. electrical
2. potential
3. Heat
4. wind
5. Mechanical

Q.

If energy is always conserved in a chemical or physical process then why is there an energy crisis?

1. Energy is getting lost in the universe.

2. Energy can never be tranformed.

3. Energy is getting destroyed.

4. Energy is dissipated from more usable form to less usable form.

Q.

Explain Laws of Thermodynamics.

Q. Notes of work and energy

Q.

Name the fuels used for household purposes.

Q. What do you mean by change in internal energy?
Please elaborate and also how it is equal to delta u

Q.

The conversion of part of energy into an unuseful form of energy is called ______

Q.

Which of the following is not correct for an ideal gas as per the first law of thermodynamics?

1. Adiabatic $∆U=-w$

2. Isothermal $q=-w$

3. cyclic $q=-w$

4. Isochoric $∆U=q$

Q.

List any two criteria for selecting a good fuel.

Q. Which of the following are qualities of an ideal fuel?

1. Economical
2. Pollution free
3. Supports life
4. High energy

Q. Biological magnification is highest in food consumed by ________.

1. humans
2. snakes
3. insects
4. reptiles

Q.

What are fuels? Give two examples of modern fuels.

Q.

With the help of an example illustrate conservation of mechanical energy.

Q. Statement 1: Energy can neither be created nor destroyed.

Statement 2: Energy cannot be converted from one form to another.

1. Only statement​ 1 is correct.
2. Only statement​ 2 is correct.
3. Both statements are correct.
4. Neither of the statements is correct.

Q. First laws of thermodynamics states that total energy of an isolated system is constant and energy can neither be created nor be destroyed but can be transformed from one form to another.

1. True
2. False

Q.

What is the first law of thermodynamics for a closed system?

Q. Question 19
A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back? $(g=10m{s}^{-2})$

Q. Question 10
An object of mass $40kg$ is raised to a height of $5m$ above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.

Q. Two boys A and B are standing at two positions as shown in the diagram. Each step is 20 cm high and 20 cm wide. The potential energy is assumed to be zero at the ground. Consider $g=10m/s^2$ and assume that there is no loss of energy.


What is the kinetic energy of the ball at the point of release?

1. 10.5 J
2. 8 J
3. 0 J
4. 10 J

Q.

A satellite gets unstable in its orbit and starts to fall towards earth and also starts burning. If the satellite had a potential energy of 1000 J initially and by the time it reaches the surface of the earth it attains a kinetic energy of 500 J, then how much energy is spent in heating the satellite?

1. None of These

2. 1000J

3. 5000J

4. 500J

Q.

Give one word/a few words for each of the following.

Fuel used in vehicle

Q. is something that is derived from the utilization of physical or chemical resources and is indestructible.

1. Momentum
2. Mass
3. Energy

Q.

We know that If a ball of mass 1 kg is kept at a height 10 m possesses potential energy 'mgh' i.e. $(1\times 10\times 10)=100$ J.

(Take earth surface as the reference, where m = mass of the object, g = acceleration due to gravity, h = height of the object from the earth's surface)
What will be the kinetic energy of the ball when the ball is allowed to freely fall from a height 10m from the surface of the earth and hits the ground?
(Take $g=10\frac{m}{s^2}$ and neglect air drag)

1. 10 J

2. 0 J

3. 100 J

4. 50 J

Q. An object of mass $40kg$ is raised to a height of $5m$ above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.

Q.

List three characteristic of a good source of energy and mention any three qualities of good fuel.

Q.

To make the radiating power of a surface as small as possible:

1. The surface is made polished

2. All the above

3. The surface is made smooth.

4. The surface is made shiny.

Q. Two boys A and B are standing at two positions as shown in the diagram. Each step is 20 cm high and 20 cm wide. The potential energy is assumed to be zero at the ground. Consider $g=10m/s^2$ and assume that there is no loss of energy.


What is the kinetic energy of the ball at the point of release?

1. 10.5 J
2. 8 J
3. 0 J
4. 10 J

Q. Question 2
What is a good fuel?