NEET UG Physics Practice Paper – Electrostatics (Set 7)

Attempt all 30 MCQs below and check your score instantly with detailed explanations.

1. Coulomb’s law states force is proportional to:

1/r²
r²
r
constant

2. SI unit of electric field is:

N/C
Volt
Joule
Watt

3. Electric field due to point charge is:

kq/r²
kqr²
q/r
r/q

4. Electric potential is:

Work/charge
Charge/work
Force/charge
Energy

5. Unit of electric potential:

Volt
Ampere
Joule
Watt

6. Work done in moving charge depends on:

Path
Initial point
Final point
Both b & c

7. Electric field inside conductor is:

Zero
Maximum
Infinite
Constant

8. Gauss law relates:

Charge & flux
Force & mass
Energy & work
Current

9. Electric flux unit is:

Nm²/C
Volt
Ampere
Joule

10. Capacitance is defined as:

Q/V
V/Q
QV
V²

11. Unit of capacitance:

Farad
Volt
Ampere
Joule

12. Energy stored in capacitor:

½CV²
CV
V²
QV

13. Capacitance increases with:

Area
Distance
Charge
None

14. Parallel plate capacitor depends on:

Area & distance
Charge only
Voltage
Time

15. Dielectric increases capacitance by:

k times
decreases
zero
none

16. Electric dipole moment is:

q×d
q/d
d/q
q+d

17. Field of dipole varies as:

1/r³
1/r²
r
constant

18. Torque on dipole is:

pE sinθ
pE cosθ
pE
zero

19. Potential due to dipole varies as:

1/r²
1/r³
r
constant

20. Electric lines of force:

never cross
cross
circular
none

21. Field at center of charged ring:

zero
max
infinite
constant

22. Equipotential surface:

constant V
varying V
zero
infinite

23. Potential energy of charge:

qV
V/q
q/V
none

24. Relation between E and V:

E = -dV/dr
V = Ed
E = V
none

25. Work done in closed path:

zero
max
infinite
constant

26. Electric field direction:

+ to –
– to +
random
none

27. Capacitance in series:

decreases
increases
same
zero

28. Capacitance in parallel:

increases
decreases
zero
same

29. Breakdown occurs due to:

high voltage
low voltage
zero voltage
none

30. Permittivity unit:

F/m
N
Volt
Joule

Submit

NEET UG Physics Notes – Electrostatics (Set 7)

Electrostatics is a high-weightage and concept-driven topic in NEET UG Physics. It forms the foundation for later topics like current electricity, capacitance, and electromagnetism. The questions in this set cover Coulomb’s law, electric field, potential, capacitance, Gauss law, and dipole concepts.

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1. Coulomb’s Law

Coulomb’s law describes the force between two point charges.$$F = k \frac{q_1 q_2}{r^2}$$F=kr2q1​q2​​

Key Points:

• Force is directly proportional to product of charges
• Inversely proportional to square of distance
• Acts along the line joining charges
• Like charges repel, unlike attract

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2. Electric Field (E)

Electric field is the force experienced per unit charge.$$E = \frac{F}{q}$$E=qF​

For a point charge:$$E = k \frac{q}{r^2}$$E=kr2q​

Important Concepts:

• Direction: From positive to negative
• Unit: N/C
• Electric field inside conductor = 0

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3. Electric Potential (V)

Electric potential is the work done per unit charge.$$V = \frac{W}{q}$$V=qW​

For a point charge:$$V = k \frac{q}{r}$$V=krq​

Key Insights:

• Scalar quantity (no direction)
• Unit: Volt
• Potential can exist even if field is zero

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4. Relation Between Electric Field and Potential

$$E = -\frac{dV}{dr}$$E=−drdV​

Meaning:

• Electric field is the rate of change of potential
• Negative sign shows direction towards decreasing potential

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5. Electric Flux and Gauss’s Law

Electric Flux:

$$\Phi = EA \cos\theta$$Φ=EAcosθ

Gauss Law:

$$\Phi = \frac{q_{enc}}{\varepsilon_0}$$Φ=ε0​qenc​​

Applications:

• Finding electric field in symmetric cases:
  • Sphere
  • Cylinder
  • Infinite plane

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6. Electric Field Lines

Properties:

• Start from positive and end at negative
• Never intersect
• Density represents field strength
• Perpendicular to conductor surface

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7. Equipotential Surfaces

Surfaces where potential is constant.

Important Facts:

• No work is done moving charge along it
• Electric field is perpendicular to surface

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8. Electric Dipole

A system of two equal and opposite charges separated by distance.

Dipole Moment:

$$p = q \times d$$p=q×d

Electric Field:

• Along axis: $E \propto \frac{1}{r^3}$E∝r31​

Torque on Dipole:

$$\tau = pE \sin\theta$$τ=pEsinθ

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9. Capacitance

Capacitance is ability to store charge.$$C = \frac{Q}{V}$$C=VQ​

Parallel Plate Capacitor:

$$C = \frac{\varepsilon_0 A}{d}$$C=dε0​A​

Where:

• $A$A = Area
• $d$d = Distance

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10. Effect of Dielectric

If dielectric is inserted:$$C = k \frac{\varepsilon_0 A}{d}$$C=kdε0​A​

Key Points:

• Capacitance increases by factor k
• Electric field decreases

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11. Energy Stored in Capacitor

$$U = \frac{1}{2}CV^2$$U=21​CV2

Other Forms:

$$U = \frac{Q^2}{2C} = \frac{1}{2}QV$$U=2CQ2​=21​QV

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12. Combination of Capacitors

Series:

$$\frac{1}{C} = \frac{1}{C_1} + \frac{1}{C_2}$$C1​=C1​1​+C2​1​

• Capacitance decreases

Parallel:

$$C = C_1 + C_2$$C=C1​+C2​

• Capacitance increases

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13. Potential Energy

$$U = qV$$U=qV

Important Insight:

• Depends on charge and potential
• Helps in solving work-related problems

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14. Work Done in Electric Field

• Depends only on initial and final position
• Independent of path (conservative field)

$$W = q(V_1 – V_2)$$W=q(V1​−V2​)

• Work done in closed loop = 0

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15. Breakdown of Dielectric

When electric field exceeds limit:

• Insulator becomes conductor
• Caused by high voltage

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16. Permittivity

$$\varepsilon_0$$ε0​

Unit:

$$F/m$$F/m

Role:

• Determines strength of electric interaction

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17. Important Exam Tips

Must Remember:

• $E \propto 1/r^2$E∝1/r2 (point charge)
• $V \propto 1/r$V∝1/r
• Dipole field $\propto 1/r^3$∝1/r3
• Capacitance depends on geometry

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18. Common Mistakes to Avoid

❌ Confusing electric field with potential
❌ Ignoring negative sign in $E = -dV/dr$E=−dV/dr
❌ Mixing up series and parallel capacitor formulas
❌ Forgetting units

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Conclusion

Electrostatics is formula-driven but concept-heavy. Most NEET questions are:

• Direct formula application
• Concept-based (field vs potential)
• Graph or relation-based

If you master:

• Coulomb’s law
• Electric field & potential
• Capacitance
• Gauss law

👉 You can easily score full marks in this chapter.