Figures (a) and (b) show the field lines of a positive and negative point charge respectively. The sign of the work done by the field in moving a small positive charge from Q to P and the sign of the work done by the external agency in moving a small negative charge from B to A, respectively, will be:
 

1. +, -
2. +, +
3. -, +
4. -, -

Subtopic:  Electric Potential Energy |
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NEET 2023 - Target Batch - Aryan Raj Singh
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Figures (a) and (b) show the field lines of a positive and negative point charge respectively. The kinetic energy of a small negative charge in going from B to A:

1. decreases.

2. increases.

3. remains the same.

4. first increases and then decreases.

Subtopic:  Electric Potential Energy |
 58%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Four charges are arranged at the corners of a square ABCD of side d, as shown in the figure. The work required to put together this arrangement will be:

1. -q24πε0d4-2
2. -q24πε0d2-2
3. -q24πε0d4+2
4. -q24πε0d2+2

Subtopic:  Electric Potential Energy |
 57%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Four charges are arranged at the corners of a square ABCD of side d, as shown in the figure. A charge q0 is brought from  to the centre E of the square, the four charges being held fixed at its corners. How much work is needed to do this?

1. -q24πε0d4-2
2. zero
3. -q24πε0d4+2
4. -q24πε0d2+2

Subtopic:  Electric Potential Energy |
 64%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The electrostatic potential energy of a system consisting of two charges 7 µC and –2 µC (and with no external field) placed at (–9 cm, 0, 0) and (9 cm, 0, 0) respectively is:

1. 0.2 J

2. -0.7 J

3. -0.2 J

4. 0.7 J

Subtopic:  Electric Potential Energy |
 78%
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NEET 2023 - Target Batch - Aryan Raj Singh
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How much work is required to separate two charges  7 µC and –2 µC (and with no external field) placed at (–9 cm, 0, 0) and (9 cm, 0, 0) infinitely away from each other?

1. 0.2 J

2. -0.7 J

3. -0.2 J

4. 0.7 J

Subtopic:  Electric Potential Energy |
 60%
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NEET 2023 - Target Batch - Aryan Raj Singh
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The electrostatic potential energy of a system consisting of two charges 7 µC and –2 µC (in an external electric field E A(1/r2); A = 9 × 105 C m–2) placed at (–9 cm, 0, 0) and (9 cm, 0, 0) respectively is:

1. 34 J

2. 49.3 J

3. 47 J

4. 43 J

Subtopic:  Electric Potential Energy |
 65%
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NEET 2023 - Target Batch - Aryan Raj Singh
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A molecule of a substance has a permanent electric dipole moment of magnitude 10–29 C m. A mole of this substance is polarised (at low temperature) by applying a strong electrostatic field of magnitude 106 V m–1. The direction of the field is suddenly changed by an angle of 600. The heat released by the substance in aligning its dipoles along the new direction of the field is: (For simplicity, assume 100% polarisation of the sample).

1. 6 J

2. 8 J

3. 3 J

4. 4 J

Subtopic:  Energy of Dipole in an External Field |
 52%
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NEET 2023 - Target Batch - Aryan Raj Singh
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Which one of the following is wrong?

1. A comb run through one’s dry hair attracts small bits of paper.
2. Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting.
3. Vehicles carrying inflammable materials usually have metallic ropes touching the ground during motion.
4. A bird perches on a bare high power line and gets a fatal shock. A man standing on the ground touches the same line and nothing happens to the man.

Subtopic:  Electrostatic Shielding |
 69%
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NEET 2023 - Target Batch - Aryan Raj Singh
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A slab of material of dielectric constant K has the same area as the plates of a parallel-plate capacitor of capacitance C0 but has a thickness (3/4)d, where d is the separation of the plates. What is the capacitance of the capacitor when the slab is inserted between the plates?

1. 4KK+3C0
2. 2KK+2C0
3. C0
4. 34C0

Subtopic:  Capacitance |
 75%
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NEET 2023 - Target Batch - Aryan Raj Singh
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