Page 266 - Basic Electrical Engineering

a. 30 Ω, 40 Ω, 60 Ω, 120 Ω
b. 15 Ω, 30 Ω, 60 Ω, 120 Ω
c. 15 Ω, 20 Ω, 25 Ω, 30 Ω
d. 4 Ω, 3 Ω, 2 Ω, 1 Ω.

22. The resistance of a wire is 6 Ω. The wire is drawn such that its length increases three times.
The resistance of the elongated wire will be (note volume remaining same, if length is
increased, area of cross section will decrease proportionately)

a. 18 Ω
b. 36 Ω
c. 54 Ω
d. 6 Ω.

23. Resistivity of a conductor depends upon

a. length of the conductor
b. area of cross-section of the conductor
c. type or nature of the material
d. all the factors as in (a), (b), and (c).

24. A conductor of length l and diameter d has a resistance of R Ohms. The diameter of the
conductor is halved and its length is doubled. What will be the value of resistance of the
conductor?

a. 2R Ω
b. 4R Ω
c. 8R Ω

d. Ω.

25. Two resistances of value 12 Ω and 8 Ω are connected in parallel and the combination is
connected in series with another resistance of value 5.2 Ω. This series parallel circuit is
connected across a 100 V supply. The total current drawn will be

a. 10 A
b. 3.96 A
c. 20 A
d. 5 A.

26. With the increase in temperature

a. the resistance of metal will increase and that of insulator will decrease
b. the resistance of metal will decrease and that of insulator will increase
c. resistance of both metal and insulator will increase
d. resistance of both metal and insulator will decrease.