Basic Electrical Engineering Quiz: Test!

1. What is the unit of current?

Ampere

Voltage

Meter

None of above

Explanation

2. The Curve representing Ohm's law is?

Linear

Hyperbolic

Parabolic

Triangular

Explanation

3. An electric heater draws 3.5 A from a 110 V source. The resistance of the heating elements is approximately?

31Ω

3.1Ω

385Ω

38.5Ω

V=I*R

R=V/I

=110/3.5

=31Ω

Explanation

V=I*R

R=V/I

=110/3.5

=31Ω

4. The SI unit of electrical energy is?

Watt-Second

Joule

KWh

Volt-Ampere Second

Joule is the SI Unit of Energy all others are the unit of Energy but not the SI Unit of energy.

Explanation

Joule is the SI Unit of Energy all others are the unit of Energy but not the SI Unit of energy.

5. Active Element in the circuit is one which

Dissipates Energy

Receive Energy

Both receives and supplies

Supplies energy

Definition :- Active elements in the circuit is one which supplies energy

Explanation

Definition :- Active elements in the circuit is one which supplies energy

6. Which of the following materials possesses the least specific resistivity?

Aluminium

Copper

Silver

Iron

None of Above

The resistivity of silver is about 1.59 × 10−8 Ωm at 20 degrees Celsius.

Explanation

The resistivity of silver is about 1.59 × 10−8 Ωm at 20 degrees Celsius.

7. Four resistances 2Ω,4Ω,5Ω,20Ω

1Ω

2Ω

4Ω

5Ω

1/R=1/R₁+1/R₁+1/R₁+1/R₁

=1/2+1/4+1/5+1/20

=10+5+4+1/20

=20/20

=1Ω

Explanation

1/R=1/R₁+1/R₁+1/R₁+1/R₁

=1/2+1/4+1/5+1/20

=10+5+4+1/20

=20/20

=1Ω

8. Two wires A and B of the same Material but of different lengths L and 2L have the radius r and 2r respectively. The ratio of specific resistance will be?

1:4

1:8

1:1

1:2

As the materials are same (p_A=p_B) the ratio will be 1:1

Explanation

As the materials are same (p_A=p_B) the ratio will be 1:1

9. Electrical conductivity of metals is typically of the order of (in Ω^-1*m^-1)

107

105

10-4

10-6

Metals have high electrical conductivity due to the presence of free electrons that can easily move through the material. The unit of electrical conductivity is Ω-1*m-1, which represents the ease with which electric current can flow through a material. A conductivity value of 107 Ω-1*m-1 indicates a very high conductivity, meaning that metals can conduct electricity very effectively.

Explanation

Metals have high electrical conductivity due to the presence of free electrons that can easily move through the material. The unit of electrical conductivity is Ω-1*m-1, which represents the ease with which electric current can flow through a material. A conductivity value of 107 Ω-1*m-1 indicates a very high conductivity, meaning that metals can conduct electricity very effectively.

10. We have three resistances each of 1Ω,2Ω and 3Ω. If all the three resistances are to be connected in a circuit, how many different values of equivalent resistances are possible?

Five

Six

Seven

Eight

R1=1Ω,R2=1Ω R3=1Ω

1) R1, R2, R3 in series

2)R1, R2, R3 in parallel

3)R1,in series with parallel combination R2 &R3

4)R2,in series with parallel combination R1 &R3

5)R3,in series with parallel combination R1 &R2

6)R1,in parallel with series combination R2 &R3

7)R2,in parallel with series combination R1 &R3

8)R3,in parallel with series combination R2 &R1

Explanation

R1=1Ω,R2=1Ω R3=1Ω

1) R1, R2, R3 in series

2)R1, R2, R3 in parallel

3)R1,in series with parallel combination R2 &R3

4)R2,in series with parallel combination R1 &R3

5)R3,in series with parallel combination R1 &R2

6)R1,in parallel with series combination R2 &R3

7)R2,in parallel with series combination R1 &R3

8)R3,in parallel with series combination R2 &R1