NEET UG - Electrical resistance, V I characteristics of Ohmic and non Ohmic conductors, electrical energy and power Question Bank with Options

1. Which physical quantity is represented by the slope of the V-I graph for an ohmic conductor?

A) Current

B) Voltage

C) Resistance

D) Conductance

2. The V-I characteristic of a semiconductor device shows that as voltage increases, resistance:

A) Increases linearly

B) Decreases non-linearly

C) Remains constant

D) First increases then decreases

3. What is the power consumed by a resistor of 20 Ohms connected to a 10V source?

A) 0.5 Watts

B) 2 Watts

C) 5 Watts

D) 50 Watts

4. A filament bulb's resistance increases as it heats up. This is because of:

A) The decreasing number of free electrons

B) The increasing atomic vibrations and collisions

C) The change in the material's resistivity at high temperatures

D) The non-linear relationship between voltage and current

5. Which of the following statements is INCORRECT regarding electrical resistance?

A) Resistance increases with length.

B) Resistance decreases with area of cross-section.

C) Resistance is independent of temperature.

D) Resistance depends on the material of the conductor.

6. For a conductor obeying Ohm's law, if the applied voltage is increased by 50%, the current through it will:

A) Increase by 25%

B) Increase by 50%

C) Increase by 100%

D) Remain the same

7. The unit 'Board of Trade Unit' (BTU) is equivalent to:

A) 1 Watt-hour

B) 1 Kilowatt-hour

C) 1 Joule

D) 1 Kilojoule

8. If a 10 Ohm resistor has a current of 2A flowing through it, the power dissipated by the resistor is:

A) 5 Watts

B) 20 Watts

C) 40 Watts

D) 100 Watts

9. The power dissipated in a resistor is maximum when:

A) Resistance is minimum

B) Voltage is maximum

C) Current is maximum

D) The load resistance matches the source resistance (in specific contexts)

10. The V-I graph of a diode is non-linear because its resistance:

A) Is constant

B) Varies with voltage and current

C) Is always zero

D) Is always infinite

11. For a given material, the resistance of a wire is inversely proportional to its:

A) Length

B) Area of cross-section

C) Temperature

D) Resistivity

12. Which of the following is a unit of electrical energy?

A) Watt

B) Volt-Ampere

C) Joule

D) Ohm-meter

13. The electrical resistance of a conductor is proportional to its:

A) Area of cross-section

B) Length

C) Reciprocal of length

D) Reciprocal of area of cross-section

14. The V-I characteristic of a tungsten filament lamp at constant voltage is:

A) A straight line passing through the origin

B) A straight line not passing through the origin

C) A curve bending away from the voltage axis

D) A curve bending towards the voltage axis

15. A 60W, 220V bulb is connected to a 220V supply. The current drawn by the bulb is:

A) 60 A

B) 220 A

C) 0.27 A

D) 3.67 A

16. If a wire of resistance R is melted and recast into a wire of half its length, the new resistance will be:

A) R/4

B) R/2

C) 2R

D) 4R

17. The electrical energy consumed by a device is equal to the product of its power and:

A) Voltage

B) Current

C) Resistance

D) Time for which it is used

18. Which of the following has a negative temperature coefficient of resistance?

A) Copper

B) Aluminum

C) Carbon

D) Tungsten

19. The V-I graph for an ohmic conductor has a constant:

A) Current

B) Voltage

C) Slope (representing resistance)

D) Power

20. When the temperature of a conductor increases, its resistance:

A) Decreases due to increased atomic vibrations

B) Increases due to increased collisions of electrons with atoms

C) Remains unchanged as resistance is a constant property

D) Becomes zero at high temperatures

21. A heating element is made of nichrome. Its resistance is R. If the wire is stretched to double its length, its new resistance will be:

A) R

B) 2R

C) 4R

D) R/2

22. The resistance of a wire of length L and uniform cross-sectional area A is R. If the length is increased to 2L and the area is reduced to A/2, the new resistance will be:

A) R/4

B) R/2

C) 2R

D) 4R

23. A device draws 2A current when connected to a 12V battery. The power consumed by the device is:

A) 6 Watts

B) 14 Watts

C) 24 Watts

D) 0.167 Watts

24. When a potential difference of 12V is applied across a resistor and a current of 3A flows, the resistance is:

A) 4 Ohms

B) 36 Ohms

C) 15 Ohms

D) 0.25 Ohms

25. The V-I characteristic of a semiconductor diode is:

A) A straight line through the origin

B) A curve that is non-linear

C) A horizontal line

D) A vertical line

26. If the voltage across a resistor is doubled, the power dissipated will increase by a factor of:

A) 2

B) 3

C) 4

D) 1/2

27. If the current through a resistor is doubled, the power dissipated will increase by a factor of:

A) 2

B) 3

C) 4

D) 1/2

28. A 100 Watt bulb is operated for 10 seconds. The energy consumed by the bulb is:

A) 10 Joules

B) 100 Joules

C) 1000 Joules

D) 0.1 Joules

29. Which of the following is NOT a formula for electrical power (P)?

A) P = V * I

B) P = I^2 * R

C) P = V^2 / R

D) P = R / (V * I)

30. If a current I flows through a conductor with resistance R for time t, the electrical energy dissipated as heat is given by Joule's law of heating, which is:

A) E = V * I * t

B) E = I^2 * R * t

C) E = V^2 * t / R

D) All of the above

31. The SI unit of electrical power is:

A) Joule

B) Volt

C) Ampere

D) Watt

32. Electrical power is defined as the rate at which:

A) Electric charge flows

B) Electric potential changes

C) Electrical energy is supplied or dissipated

D) Resistance varies

33. The SI unit of electrical energy is:

A) Watt-hour

B) Kilowatt-hour

C) Joule

D) Calorie

34. If a charge Q flows through a point in a circuit with a potential difference V across it, the electrical energy supplied or dissipated is:

A) Q / V

B) V / Q

C) V * Q

D) Q^2 * V

35. Electrical energy is the energy derived from:

A) Kinetic energy of molecules

B) Potential energy of particles

C) The flow of electric charge

D) Magnetic field interactions

36. Which material has very high resistivity and is used for making heating elements?

A) Silver

B) Aluminum

C) Nichrome

D) Iron

37. Which material has very low resistivity and is used for making connecting wires?

A) Rubber

B) Glass

C) Copper

D) Wood

38. What happens to the resistance of most metallic conductors when their temperature increases?

A) Decreases

B) Increases

C) Remains the same

D) Becomes zero

39. The SI unit of resistivity is:

A) Ohm

B) Ohm-meter

C) Siemens

D) Volt/meter

40. The relationship between resistance (R), resistivity (ρ), length (L), and area of cross-section (A) of a conductor is given by:

A) R = ρ * A / L

B) R = ρ * L / A

C) R = A / (ρ * L)

D) R = L / (ρ * A)

41. Resistivity (ρ) of a material is a property that:

A) Depends on the dimensions of the conductor

B) Is independent of the dimensions of the conductor but depends on temperature and material

C) Is always constant for all materials

D) Is the reciprocal of resistance

42. The resistance of a conductor depends on which of the following factors?

A) Length and area of cross-section only

B) Material and temperature only

C) Length, area of cross-section, material, and temperature

D) Voltage and current only

43. For a non-ohmic conductor, the V-I graph:

A) Is always a straight line

B) Is a curve or a straight line not passing through the origin

C) Passes through the origin

D) Is always perpendicular to the current axis

44. Which of the following is an example of a non-ohmic conductor?

A) A metallic wire at constant temperature

B) A carbon resistor

C) A semiconductor diode

D) An electrolyte solution

45. For an ohmic conductor, the V-I graph (potential difference vs. current) is:

A) A curve

B) A straight line passing through the origin

C) A straight line not passing through the origin

D) A parabola

46. A conductor that obeys Ohm's Law is called:

A) Non-ohmic conductor

B) Ohmic conductor

C) Semiconductor

D) Insulator

47. If a potential difference of V is applied across a conductor and a current I flows through it, its resistance R is given by:

A) R = I / V

B) R = V * I

C) R = V / I

D) R = I^2 / V

48. The SI unit of electrical resistance is:

A) Ampere

B) Volt

C) Ohm

D) Watt

49. According to Ohm's Law, for a given conductor at a constant temperature, the potential difference across the conductor is directly proportional to:

A) Its resistance

B) Its resistivity

C) The current flowing through it

D) The power dissipated

50. Which physical quantity is defined as the opposition to the flow of electric current through a conductor?

A) Electric charge

B) Electric current

C) Electrical resistance

D) Electric potential

Electrical resistance, V I characteristics of Ohmic and non Ohmic conductors, electrical energy and power - Question Bank