Page 56 - CHAPTER-1 (Electricity)

CHAPTER 1

ELECTRICITY

11. Two wires of same length and area are made of two materials of

resistivity ρ1 and ρ2. The wires are connected in parallel

combination to a source of potential V. The equivalent resistivity

for the identical length and area is

ρ ρ
(a) + (b) ρ +ρ 2
1 2
2
1
1
(c) (ρ +ρ ) (d)| − |
1
2
ρ ρ 1 2
1 2
12. Two devices are connected in parallel combination between two
points say P and Q. The physical quantity that remains the same

between the two points is

(a) current (b) voltage

(c) resistance (d) None of these

13. To get an equivalent resistance of 2 Ω using only 6 Ω resistors, the

number of resistances required is

(a) 2 (b)3

(c) 4 (d) 6

14. The least resistance that we can have by using 2 Ω, 4 Ω, 1 Ω and

100 Ω is

(a) < 100 Ω (b) < 4 Ω

(c) < 1 Ω (d) > 2

15. The equivalent resistance between A and B is

(a) 4Ω

(b) 6Ω

(c) May be 10 Ω

(d) Must be 10 Ω

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