Misconceptions about PE

Q. Twenty seven million small drops, each of radius 1mm and having a charge of 10 to the power -10 C, coalesce to form a bigger drop. Find the potential of the bigger drop.

Q. a thin non conducting disc f radius R with uniformly charged with surface chare density σ. if potential at any point on the circumference of disc be V and elestostatic potential energy of the disc be U

Q. change in potential energy of a system is the work done by an external agent in moving the charge slowly without causing acceleration. why slowly and why should there be no acceleration .

Q.

An object is dropped from a height h when is its potential energy maximum?

Q. Energy stored in spring $A=20\text{J}$, then energy stored in spring $B$ is (under same extension of the spring)

1. $20\text{J}$
2. $30\text{J}$
3. $40\text{J}$
4. $50\text{J}$

Q. Suppose all the electrons of 100 g water are lumped together to form a negatively-charged particle and all the nuclei are lumped together to form a positively-charged particle. If these two particles are placed 10.0 cm away from each other, find the force of attraction between them. Compare it with your weight.

Q.

_________ of a two particle system depends only on the seperation between the two particles.

1. Kinetic Energy

2. Total Mechanical Energy

3. Potential Energy

4. Total Energy

Q.

Calculate the force between 2 alpha particles seperated by a distance of 3.2 x 10^-11m .

Q.

I am writing a definition of potential energy, please check the correctness of this definition !!!!

this is the energy possessed by a body by virtue of its position in a vector field such as gravitational field and electric field .

Q.

what do you mean by acceleration potential?

Q. 7.What is the main difference between potential and potential energy with respect to definition?

Q. What is the relationship between acceleration potential and kinetic energy of a particle when masses are different

Q. Define the term potential energy of a body. State its different forms and give one example of each.

Q. Assertion :Electron revolves around a positively charged nucleus like a planet revolves around the sun. Reason: The force acting in both the cases is of same kind.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Three point charges 1C, 2C, 3C are placed at the corners of an eqiulateral triangle of side 1m. calculate the work done to move these charges to the corners of a smaller equilateral traingle of side 0.5m

Q.

(numerical question):-HOW FAR APART TWO PROTONS BE IF THE ELECTROSTATICS FORCE EXERTED BY ONE ON THE OTHER IS EQUAL TO WEIGHT OF THE ELECTRON ?

Q. $K$ is the force constant of a spring. The work done in increasing its extension from $l_1$ to $l_2$ will be:

1. $\frac{K}{2}(l_2+l_1)$
2. $K(l_2^2-l_1^2)$
3. $K(l_2-l_1)$
4. $\frac{K}{2}(l_2^2-l_1^2)$

Q. Energy stored in spring $A=20\text{J}$, then energy stored in spring $B$ is (under same extension of the spring)

1. $20\text{J}$
2. $30\text{J}$
3. $40\text{J}$
4. $50\text{J}$

Q. There is an object of mass 'm' at a height 'h' from the ground. When you say that the potential energy is 'mgh', which of the following is true

1. The potential energy at ground level is taken as zero
2. Potential energy at infinity is taken as zero
3. Potential energy is stored in the object
4. 'mgh' is the potential energy of earth-body system

Q. Four charges each of magnitude +Q are placed at the corners of a square of side a.What is the work done in carrying an electron from the point of intersection of diagonals to the center of a side of the square?
Ans: -4ekQ[1+(1/?5)-?2] /a

Q. The space in which a body experiences a force by virtue of its mass, is called a/an

1. magnetic field
2. electric field
3. gravitational field
4. none of these

Q. energy changes occur in.
truck climbing hill, battery charged

Q.

Position and potential energy/ ______ and electrosttic energy.

Q.

_________ of a two particle system depends only on the seperation between the two particles.

1. Kinetic Energy

2. Total Mechanical Energy

3. Potential Energy

4. Total Energy

Q. There is an object of mass 'm' at a height 'h' from the ground. When you say that the potential energy is 'mgh', which of the following is true

1. The potential energy at ground level is taken as zero
2. Potential energy at infinity is taken as zero
3. Potential energy is stored in the object
4. 'mgh' is the potential energy of earth-body system

Q. There is an object of mass 'm' at a height 'h' from the ground. When you say that the potential energy is 'mgh', which of the following is true

1. The potential energy at ground level is taken as zero
2. Potential energy at infinity is taken as zero
3. Potential energy is stored in the object
4. 'mgh' is the potential energy of earth-body system

Q. Energy stored in spring $A=20\text{J}$, then energy stored in spring $B$ is (under same extension of the spring)

1. $20\text{J}$
2. $30\text{J}$
3. $40\text{J}$
4. $50\text{J}$

Q. Why it is only the difference of potential energy which is significant and actual value at a point is not relevant.
thus there is a freedom in choosing the point where potential energy is zero

Q. What is potential