**MCQ on Resistivity**

MCQ on Resistivity. Practice Resistivity Multiple Choice Questions and Explanation.

Practice MCQ Questions with Answers for Resistivity students will gain deep knowledge in Resistivity Quiz Questions. You can practice all MCQ Questions for Class 10 Physics with Answers for CBSE Board Exam.

**Resistivity**

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Students here we are going to discuss the factors that affects the resistance of conductor i.e. length and area of cross section (keeping temperature constant). So let’s start!

**Q.1) Resistance of given wire is directly proportional to…….**

a) length b) area of cross-section c) both a and b d) none of these

Ans: a)

Explanation: a) resistance of given wire is increases with increase in length.

**Q.2) Resistance of wire is inversely proportional to…..**

a) length b) area of cross-section c) both a and b d) none of these

Ans: b)

Explanation: b) resistance of given wire is increases with decrease in area of cross-section.

**Q.3) Which among the following represents the correct formula for resistivity?**

**Q.4) SI unit of resistivity is……..**

a) Ω/m

b) Ω/m^{2}

c)Ω-m

d) m/Ω

Ans: c)

**Q.5) The reciprocal of resistivity is known as**

a) specific resistance

b) conductivity

c) inductance

d) resistance

Ans: b)

Explanation: b) reciprocal of resistivity is known as conductivity.

**Q.6) SI unit of conductivity ‘σ’ is…**

a) Ω/m

b) Ω/m^{2}

c)Ω-m

d) 1/Ω-m

Ans: c)

**Q.7) Resistance of wire of length is R1 Ω, resistance of the wire of same length but 1/4th the area is…….the initial resistance**

a) doubled

b) halved

c)quadrupled

d) quarter

Ans: c)

**Q.8) Resistance of wire of length is 100 Ω, resistance of the wire of same thickness but tripled the length is…**

a) 200 Ω

b) 300 Ω

c)400 Ω

d) 500 Ω

Ans: b)

**Q.9) Resistivity of silver rod of length L and area A is 1.5× 10 ^{-8} Ω.m, resistivity of silver rod if length increases by 3 times and area decreases by half will be**

a) 1.5× 10^{-8} Ω.m

b) 3× 10^{-8} Ω.m

c)0.5× 10^{-8} Ω.m

d) 0.25× 10^{-8} Ω.m

Ans: a)

Explanation: c) resistivity of material always remains constant.

**Q.10) Resistivity of silver rod of length L and area A is 1.5× 10 ^{-8} Ω.m Its conductivity is**

**Q.11) Constantan wire of length 2 m and area of cross-section 1 mm2has resistivity 49×10 ^{-8} Ω.m. If it carries current of 20 A, the potential difference across the wire is..**

a) 20 V

b) 40 V

c) 60 V

d) 80 V

Ans: d)

**Q.12) Resistance of material of wire is 2000 ohm when its length L and area of cross-section is A cm ^{2}. The resistance of same material of wire of length half the initial and area quadrupled the initial area will be….**

a) 2.5 Ω

b) 25 Ω

c)250 Ω

d) 2500 Ω

Ans: c)

**Q.13) Ratio of resistances of silver wires with lengths in ratio 1:3 and area in ratio 3:2 is**

a) 1:2

b) 1:3

c)3:1

d) 2:1

Ans: a)