12th class (Fsc) Physics unit 2 MCQs
chapter 2 MCQs 12th Class Physics
Current Electricity:
1. When a charge of 5µ C passes through a conductor in 2s, the current in the conductor is:
a. 2.5mA
b. 10 A
c. 2.5µA
d. 2.5 A
2. A charged conductor has charge on its:
a. Middle-surface
b. Inner-surface
c. Surrounding space
d. Outer-surface
3. A battery more a charge of 40 C around a circuit at constant rate in 20sec. The current will be:
a. 80A
b. 2A
c. 800A
d. 0.5A
4. Drift velocity of electrons is:
a. 10-3m/s
b. 10-1m/s
c. 10-4m/s
d. 10-2m/s
5. Ampere second stands for the unit of:
a. Energy
b. Charge
c. Power
d. Emf
6. Magnitude of drift velocity is the order of:
a. 10-3 m/s
b. 10-5 m/s
c. 10-3 m/s
d. 106 m/s
7. If 1×07 electron passes through a conductor is 1.0µs then the current is:
a. 2.6×10-6 A
b. 2 A
c. 1.6×10-6 A
d. 1.6 A
8. The potential difference between the head and tail of an electric eel to:
a. 800volt
b. 600volt
c. 900volt
d. 700volt
9. The heat produced by the passage of current through a resistor is:
a. H = I/Rt
b. H = I2Rt
c. H = I2/Rt
d. H = IR2t
10. Two resistances of 2Ω each are connected in parallel combination equivalent
resistance will be:
a. 1Ω
b. 4Ω
c. 8Ω
d. 2Ω
11. A charge of 4 Coulomb is in the field of intensity of 4 N/C. the force on the charge is:
a. 4 N
b. 8 N
c. 1 N
d. 16 N
12. Magnetic effect of current is used in:
a. Electric iron
b. Toaster
c. D.C battery
d. Electric motor
13. One ohm is equal to:
a. AC-1
b. VC-1
c. VA-1
d. CV-1
14. By increasing the temperature of conductor, the flow rate of charges:
a. Changes exponentially
b. Increases
c. Decreases
d. Remains constant
15. For which device the graph between V and I is:
a. Hyperbola
b. A straight line
c. Parabola
d. Curve
16. A wire of uniform area of cross-section A, length L and resistance R is cut into two equal parts. The resistivity of each part.
a. Is halved
b. Is doubled
c. Is one-fourth
d. Remain the same
17. The SI unit of temperature coefficient of resistivity is:
a. K
b. Ohm-m
c. Ohm
d. K-1
18. The reciprocal of resistance is called:
a. Conductance
b. Capacitance
c. Inductance
d. Resistance
19. ohm – m-1 is the unit of:
a. Conductance
b. Resistance
c. Conductivity
d. Resistivity
20. Specific resistance of a material depends upon:
a. Length
b. Area
c. Temperature
d. Both A & B
21. Good conductors have conductivities of the order of:
a. 102 (Ω m)-1
b. 10-7 (Ω m)-1
c. 10-2 (Ω m)-1
d. 107 (Ω m)-1
22. The SI unit of resistivity is:
a. Ω m
b. Ω m-2
c. Ω
d. Ω m-1
23. When a wire of resistance R is cut in two equal parts its resistance becomes R/2 what happens to resistivity:
a. Half
b. Double
c. One fourth
d. Same
24. Which one has negative temperature co-efficient of resistance:
a. Carbon
b. Silver
c. Steal
d. Gold
25. A certain wire has a resistance R, the resistivity of another wire of an identical material with the first, except for twice its diameter is:
a. 2R
b. 1/4R
c. Same as R
d. 4R