NEET UG Physics Practice Paper – Current Electricity (Set 8)

Attempt all 30 MCQs and check your score instantly.

1. Electric current is defined as:

Charge/time
Voltage/time
Energy/time
Power/time

2. SI unit of current:

Ampere
Volt
Ohm
Watt

3. Ohm’s law is:

V=IR
P=VI
E=mc²
F=ma

4. Resistance unit:

Ohm
Volt
Ampere
Joule

5. Resistivity depends on:

Material
Length
Area
Shape

6. Resistance formula:

ρL/A
L/ρA
A/ρL
ρA/L

7. Current density is:

I/A
V/I
IR
P/V

8. Drift velocity is proportional to:

Electric field
Temperature
Resistance
Mass

9. Mobility is:

v/E
E/v
I/V
V/I

10. Ohmic conductor obeys:

linear V-I
nonlinear
exponential
none

11. Power formula:

VI
IR
V/R
I/V

12. Joule law:

I²Rt
IR
V²
none

13. Series resistance:

add
decrease
multiply
none

14. Parallel resistance:

decrease
increase
same
none

15. EMF is:

energy/charge
force
current
resistance

16. Internal resistance affects:

current
voltage only
power only
none

17. Terminal voltage:

E – Ir
E + Ir
IR
none

18. Kirchhoff’s law is based on:

conservation laws
motion
gravity
none

19. Wheatstone bridge condition:

P/Q=R/S
P+Q
PQ
none

20. Potentiometer measures:

EMF
current
resistance
power

21. Resistivity unit:

Ωm
Ohm
Volt
Ampere

22. Conductivity is:

1/ρ
ρ
R
none

23. Temperature effect on metals:

resistance increases
decreases
constant
zero

24. Superconductors have:

zero resistance
high resistance
variable resistance
none

25. Electric power unit:

Watt
Volt
Ampere
Ohm

26. Energy unit:

Joule
Watt
Volt
Ampere

27. Ammeter resistance:

low
high
infinite
zero

28. Voltmeter resistance:

high
low
zero
none

29. Drift velocity increases with:

electric field
resistance
length
area

30. Ohm’s law valid for:

metals
semiconductors
diodes
none

Submit

NEET UG Physics Notes – Current Electricity (Set 8)

Current Electricity is a high-scoring and formula-based chapter in NEET UG Physics. It is very important because it involves direct formula application, conceptual clarity, and numerical solving. This chapter also connects with practical applications like circuits, meters, and electrical devices.

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1. Electric Current

Electric current is the rate of flow of electric charge.$$I = \frac{Q}{t}$$I=tQ​

Key Points:

• SI Unit: Ampere (A)
• Conventional current flows from positive to negative
• Actual electron flow is opposite

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2. Ohm’s Law

Ohm’s law states that current through a conductor is directly proportional to voltage.$$V = IR$$V=IR

Important Insights:

• Valid only for ohmic conductors
• Graph of V vs I is a straight line

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3. Resistance (R)

Resistance is the opposition offered to current flow.$$R = \frac{V}{I}$$R=IV​

Factors Affecting Resistance:

$$R = \rho \frac{L}{A}$$R=ρAL​

• $\rho$ρ = Resistivity
• $L$L = Length
• $A$A = Area

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4. Resistivity (ρ)

Definition:

Property of a material that determines resistance.

Key Points:

• Unit: Ω·m
• Depends only on material and temperature
• Independent of shape and size

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5. Conductivity (σ)

$$\sigma = \frac{1}{\rho}$$σ=ρ1​

Insight:

• High conductivity → good conductor
• Example: Copper, Silver

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6. Current Density (J)

$$J = \frac{I}{A}$$J=AI​

Relation:

$$J = nqv_d$$J=nqvd​

• $n$n = charge carriers
• $q$q = charge
• $v_d$vd​ = drift velocity

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7. Drift Velocity

Drift velocity is the average velocity of electrons under electric field.$$v_d \propto E$$vd​∝E

Important Concept:

• Very small in magnitude
• Responsible for current flow

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8. Mobility (μ)

$$\mu = \frac{v_d}{E}$$μ=Evd​​

Meaning:

• Ease with which charge carriers move in a material

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9. Electric Power

$$P = VI$$P=VI

Other Forms:

$$P = I^2R = \frac{V^2}{R}$$P=I2R=RV2​

Unit:

• Watt (W)

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10. Heating Effect of Current (Joule’s Law)

$$H = I^2Rt$$H=I2Rt

Applications:

• Electric heaters
• Electric irons

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11. Combination of Resistances

Series Combination:

$$R = R_1 + R_2 + R_3$$R=R1​+R2​+R3​

• Current same
• Voltage divides

Parallel Combination:

$$\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2}$$R1​=R1​1​+R2​1​

• Voltage same
• Current divides

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12. EMF and Potential Difference

EMF (E):

• Energy supplied per unit charge

Terminal Voltage:

$$V = E – Ir$$V=E−Ir

Where:

• $r$r = internal resistance

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13. Internal Resistance

Definition:

Resistance inside a cell.

Effect:

• Reduces current
• Causes voltage drop

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14. Kirchhoff’s Laws

1. Junction Law (Current Law):

$$\sum I = 0$$∑I=0

• Based on conservation of charge

2. Loop Law (Voltage Law):

$$\sum V = 0$$∑V=0

• Based on conservation of energy

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15. Wheatstone Bridge

Used to measure unknown resistance.

Balanced Condition:

$$\frac{P}{Q} = \frac{R}{S}$$QP​=SR​

Key Feature:

• No current flows through galvanometer when balanced

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16. Potentiometer

Uses:

• Measure EMF
• Compare EMFs
• Find internal resistance

Advantage:

• More accurate than voltmeter (no current drawn)

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17. Temperature Effect

Metals:

• Resistance increases with temperature

Semiconductors:

• Resistance decreases

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18. Superconductors

Key Property:

• Zero resistance below critical temperature

Applications:

• MRI machines
• Magnetic levitation

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19. Measuring Instruments

Ammeter:

• Measures current
• Very low resistance
• Connected in series

Voltmeter:

• Measures voltage
• Very high resistance
• Connected in parallel

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20. Important NEET Tips

Must Remember:

• $V = IR$V=IR
• $R = \rho L/A$R=ρL/A
• $P = VI$P=VI
• $H = I^2Rt$H=I2Rt

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21. Common Mistakes

❌ Confusing resistivity with resistance
❌ Using wrong formula for series/parallel
❌ Ignoring internal resistance
❌ Not converting units properly

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Conclusion

Current Electricity is one of the easiest scoring chapters in NEET if concepts are clear.

Focus on:

• Ohm’s law
• Resistance formulas
• Circuit analysis
• Kirchhoff laws

👉 Most questions are direct and formula-based, so strong fundamentals can guarantee full marks.