Electric Circuits Answers

A 2Ω and a 3Ω resistors in parallel are connected in series to a 4Ω resistor. The combination is then connected across a 12V battery having internal resistance of 1Ω as shown in the figure. What is the equivalent resistance of the circuit?

a. 9.2Ω
b. 6.2Ω
c. 2.2Ω
d. 7.2Ω

Electrical energy is sold by PHCN in units of kilowatt-hour (kWh). The lighting of a house is done with five 60W bulbs which are switched on for approximately three hours per day. What is the lighting bill for the household over a period of 30days at the rate of N1.20 per kilowatt-hour?

a. N1.50
b. N25.30
c. N32.40
d. N52.20

A battery has emf 13.2V and internal resistance 24mΩ. If the load current is 20.0A, find the terminal voltage o f the battery.

a. 12.7V
b. 14.5V
c. 16.8V
d. 17.7V

14 A battery of e.m.f. and negligible internal resistance is connected to two resistors of resistances R1 and R2 as shown in the figure. What is the potential difference across the resistor of resistance R2?

a. E(R1+R2)/R1
b. ER2/(R1+R2)
c. E(R1+R2)/R2
d. ER2/R1

A Nichrome wire is 1.0m long and 1.0mm^2 in cross-sectional area. It carries a current of 4.0A when a potential difference of 2V is applied between its ends. Calculate the conductivity of the wire.

a. (2MΩm)^−1
b. (4kΩm)^−1
c. (2mΩm)^−1
d. (4Ωm)^−1

A copper wire has resistance of 2.0Ω at 0oC and 2.26Ω at 30 degrees Celsius. What is its resistance at 50 degrees Celsius?

a. 2.43Ω
b. 3.34Ω
c. 1.52Ω
d. 5.31Ω

A current flows in a wire of circular cross-section with the free electrons traveling with a mean drift velocity v. If an equal current flows in a wire of the same material but of twice the radius, what is the new mean drift velocity?

a. v/4
b. v/2
c. 2v
d. 4v

Calculate the resistance of 180m of silver wire having a cross section of 0:33mm^2. The resistivity of silver is 1:6×10^−8Ωm

a. 11.2Ω
b. 9.6Ω
c. 14.6Ω
d. 75Ω

What are the dimensions of electrical resistance?

a. MLT^−2A^−1
b. M^2L^2TAL^−2
c. ML^2T^−3A^−2
d. None of the above