Potential Energy Is Defined for a System

Q. In any natural or spontaneous process the energy of the universe remains constant but the entropy of universe always increases. Explain.

Q. Paragraph for below question
A uniform rod of mass 4 kg is suspended using two equal length strings (1) and (2), tied at the end points A and B respectively. Length of rod is 100 cm. Another mass 2 kg is suspended at 20 cm from A as shown. Under equilibrium conditions, answer the following question : (Take g = 10 m/s²)
Q. Tension in the right string, T₂ is नीचे दिए गए प्रश्न के लिए अनुच्छेद
4 kg द्रव्यमान की एकसमान छड़ को दो समान लम्बाई की डोरियों (1) व (2) द्वारा सिरे बिन्दुओं क्रमशः A व B से बांधकर लटकाया जाता हैं। छड़ की लम्बाई 100 cm है। 2 kg के अन्य द्रव्यमान को दर्शाए अनुसार A से 20 cm पर लटकाया जाता है। साम्य स्थितियों में, निम्नलिखित प्रश्न का उत्तर दीजिए। (g = 10 m/s² लीजिए)
प्रश्न. दायीं डोरी में तनाव T₂ है

1. 24 N
2. 20 N
3. 22 N
4. 26 N

Q. Two equal negative charges $-q$ each are fixed at points $(0,-a)$ and $(0,a)$ on y-axis. A positive charge $Q$ is released from rest at the point $(2a,0)$ on the $x$ - axis. The charge $Q$ will

1. execute simple harmonic motion about the origin
2. move to the origin and remain at rest
3. move to infinity
4. execute oscillatory but not simple harmonic motion

Q. Two equal negative charges $-q$ each are fixed at points $(0,-a)$ and $(0,a)$ on y-axis. A positive charge $Q$ is released from rest at the point $(2a,0)$ on the $x$ - axis. The charge $Q$ will

1. execute simple harmonic motion about the origin
2. move to the origin and remain at rest
3. move to infinity
4. execute oscillatory but not simple harmonic motion

Q.

When you lift an apple from a table to your mouth to enjoy its deliciousness, then

1. P.E of the apple increases.

2. P.E of Earth decreases
3. P.E of Earth-apple system increases
4. P.E of Earth-apple system decreases.

Q.

Statement 1: Potential energy depends on the choice of reference point.

Statement 2: Change in potential energy depends upon the choice of reference point.

1. Statement 1 is true, statement 2 is true.
2. Statement 1 is true, statement 2 is false.
3. Statement 1 is false, statement 2 is true.
4. Statement 1 is false, statement 2 is false.

Q. The gravitational field in a region is given by $\overrightarrow{\mathrm{E}}=\left(5\mathrm{N}{\mathrm{kg}}^{-1}\right)\overrightarrow{i}+\left(12\mathrm{N}{\mathrm{kg}}^{-1}\right)\overrightarrow{j}$. (a) Find the magnitude of the gravitational force acting on a particle of mass 2 kg placed at the origin. (b) Find the potential at the points (12 m, 0) and (0, 5 m) if the potential at the origin is taken to be zero. (c) Find the change in gravitational potential energy if a particle of mass 2 kg is taken from the origin to the point (12 m, 5 m). (d) Find the change in potential energy if the particle is taken from (12 m, 0) to (0, 5 m).

Q.

When you lift an apple from a table to your mouth to enjoy its deliciousness, then

1. P.E of the apple increases.

2. P.E of Earth decreases
3. P.E of Earth-apple system increases
4. P.E of Earth-apple system decreases.

Q.

Gravitational Potential is:

1. negative, vector quantity , unit JKg^-1

2. negative, scalar quantity , unit JKg^-1

3. positive, scalar quantity , unit JKg^-1

4. positive, vector quantity , unit JKg^-1

Q. If the P.E of a system decreases by 40 J while the K.E remains constant, then the work done by external agent will be.

1. 40 J
2. -40 J
3. 20 J
4. 0 J