MCQS

1. The SI unit of resistance is:
A) Siemens
B) Ohm
C) Mho
D) Volt

2. Resistance is directly proportional to:
A) Area of cross-section
B) Length of conductor
C) Conductivity
D) Temperature only

3. Resistance is inversely proportional to:
A) Length
B) Resistivity
C) Area of cross-section
D) Current

4. Resistivity is represented by:
A) κ
B) G

C) ρ
D) R

5. Conductance is the reciprocal of:
A) Current
B) Voltage
C) Resistance
D) Resistivity

6. Unit of conductance is:
A) Ohm
B) Siemens
C) Volt
D) Ampere

7. Conductivity is the reciprocal of:
A) Resistance

B) Resistivity
C) Current
D) Potential difference

8. Resistance is measured using:
A) Potentiometer
B) Galvanometer
C) Wheatstone bridge
D) Voltmeter

9. Materials with very high conductivity are called:
A) Insulators
B) Semiconductors
C) Conductors
D) Superconductors

10. Which is a semiconductor?
A) Copper
B) Glass
C) Silicon
D) Silver

11. Materials with zero resistivity are called:
A) Conductors
B) Semiconductors
C) Insulators
D) Superconductors

12. Metallic conductance is due to movement of:
A) Protons
B) Ions
C) Electrons
D) Neutrons

13. Metallic conductance decreases with:
A) Increase in temperature
B) Increase in pressure
C) Increase in length
D) Increase in area

14. Electrolytic conductance is due to:
A) Electrons
B) Ions
C) Atoms
D) Molecules

15. Conductivity of electrolytic solutions increases with:
A) Decrease in concentration
B) Increase in temperature
C) Increase in viscosity
D) Decrease in ions

16. Pure water has conductivity due to:
A) Metal ions
B) H⁺ and OH⁻ ions
C) Electrons
D) Salt impurities only

17. Which factor affects ionic conductivity?
A) Nature of solvent
B) Ion size
C) Temperature
D) All of these

18. In metallic conductance, composition of conductor:
A) Changes continuously
B) Remains unchanged
C) Decomposes
D) Forms ions

19. In electrolysis, prolonged passage of direct current may:
A) Leave solution unchanged
B) Increase resistance only
C) Change composition of solution
D) Stop ion movement

20. Graphite is a:
A) Semiconductor
B) Insulator
C) Conducting non-metal
D) Superconductor

21. 1 S cm⁻¹ equals:
A) 10 S m⁻¹
B) 100 S m⁻¹
C) 1000 S m⁻¹
D) 0.01 S m⁻¹

22. 1 Ω cm equals:
2 A) 100 Ω m B) 10 Ω m C) 0.01 Ω m D) 1 Ω m
23. Which shows infinite conductivity?
A) Copper
B) Silicon
C) Superconductor
D) Graphite

24. Conducting polymers include:
A) Polyaniline
B) Polypyrrole
C) Polyacetylene
D) All of these

25. Nobel Prize (2000) for conducting polymers was awarded to:
A) Rutherford, Bohr, Chadwick
B) MacDiarmid, Heeger, Shirakawa
C) Arrhenius, Faraday, Nernst
D) Dalton, Thomson, Planck

26. Charge carriers in electrolytic conductance are:
A) Electrons only
B) Positive ions only
C) Positive and negative ions
D) Protons only

27. Which has intermediate conductivity?
A) Rubber
B) Silicon
C) Copper
D) Glass

28. Conductivity of pure water is approximately:
A) 3.5 × 10⁻⁵ S m⁻¹
B) 3.5 × 10⁵ S m⁻¹
C) 35 S m⁻¹
D) Zero

29. Lower viscosity of solvent causes:
A) Lower conductivity
B) Higher conductivity
C) No effect
D) Infinite resistance

30. Which statement is incorrect?
A) Metallic conductance is electronic conductance
B) Electrolytic conductance is ionic conductance
C) Metallic conductance increases with temperature
D) Conductivity depends on concentration