MCQ
21. The unit of resistivity is-
Ohms
Ohm/Sqm
Ohm-m
None
22. What is the resistance-power of an electric iron with 220V and 1100 watt?
11 Ω
33 Ω
22 Ω
44 Ω
23. Unit of magnetic flux density-
ব্যাখ্যা: Magnetic Flux density has the dimension mas per time squared electric current. The St derived unit of magnetic flux density is the tesla.
tesla
lux
weber
henry
24. The resistivity depends upon-
area
material
length
All of these
25. Unit of electrical energy is:
Newton-meter
Watt-sec
Watt
BTU
26. An electric heater is marked 2000W, 200V; the resistance of the coil is--Ω
0.1
20
1/20
200
27. Resistance of a conductor of diameter and length L is R ohm. It the diameter of the conductor is halved and its length is doubled the resistance will be-.
2R ohm
4R ohm
8R ohm
3R ohm
28. The resistivity of the conductor depends on-
ব্যাখ্যা: Resistivity depends upon nature of material and physical conditions.
area of the conductor
length of the conductor
type of material
none
29. What voltage drop will be there across a 1kW flood light whose resistance when hot is 40 Ω ?
100V
50V
150V
200V
30. Semiconductor-এর temperature coefficient of resistance--
ব্যাখ্যা: Semiconductor-এর temperature coefficient of resistance Negative
Negative
Zero
Positive
কোনোটিই নয়
31. Resistance depends on:
Cross section
Length
Material
All
32. How many 60-watt bulbs will be safe for a home with main meter of 6 amp and 220 volts?
6
10
11
22
33. Which one is a semiconductor material?
Phosphorous
Silicon
Rubber
Aluminium
34. The minimum dielectric stress in a cable is at-
ব্যাখ্যা: Equation of Resistivity of a wire is- So, resistivity of wire is directly proportional to cross section area (A) and inversly proportional to length (L) of wire.
conductor
surface centre of conductor
lead sheath
none of the above
35. Which of the following quantites consist of unit as WATT?
ব্যাখ্যা: The St unit of power is the watt and it is discover by the Scottish Engineer James Watt. Power is the rate of consumption of electric energy. So, it is equivalent joules per second.
force
charge
current
power
36. 1 coulomb is equal to?
6.24 x 10^18 electron-charge
6.28 x 10^16 electron charge
682 x 10^18 electron charge
6.82 x 10^-18 electron change
37. Which quantity consists of a unit 1 kWh?
ব্যাখ্যা: 1 kWh is the amount of energy used by a 1 kW (1000 watt) resistance for 1 hour. Energy = Power x Time
energy
power
time
charge
38. What type of material is Silicon (Si)?
Conductor
Semiconductor
Insulator
Good conductor
39. Energy consumption of a 100-watt bulb for ten hours is
1000kWh
1 unit
100kWh
1kW
40. SI unit of electrical capacitance--
ohm
farad
henry
coulomb