(ii) Thus, if we take 1 metre long piece of a substance having … The resistivity of sample C is of the order of an alloy, so sample C is suitable for heating elements of electrical appliances. The other differences between them are explained below in the comparison chart. Resistivity is the resistance per unit length and cross-sectional area. Electric conductivity may be represented by the Greek letter σ (sigma), κ (kappa), or γ (gamma). At 20 0 C the resistivity value for silver is 1.59×10-8, for copper 1.68×10-8. are solved by group of students and teacher of Class 10, which is also the largest student community of Class 10. NCERT Solutions for Class 10 Science Electricity. All the resistivity values for various materials can be found in a table. Electrical conductivity is the reciprocal quantity of resistivity. What Is Resistivity where ρ (rho) is called resistivity of the material of conductor. Two metallic wires A and B are connected in series. Relationship Between Resistivity ρ and Conductivity s. Resistivity is a measure of how well a material is at resisting the flow of current just like a frictional force while conductivity is a measure of how well, a conductor allows the flow of current through it just like a water pipe. Wire A has length l and radius r, while wire B has length 2l and radius 2r. Difference Between Resistance & Resistivity One of the major difference between the resistance and the resistivity of the material is that the resistance opposes the flow of free electrons whereas the resistivity is the property of the material which defines the resistance of the material having specific dimension. The resistivity of copper is around 1.7 x 10-8 ohm metre (or 17. nΩm), although figures will vary slightly according to the grade of the copper Materials like copper and even aluminium provide low levels of resistivity and this makes them ideal for use as electrical wires and cables - … The resistivity of an exceedingly good electrical conductor, such as hard-drawn copper, at 20° C (68° F) is 1.77 × 10-8 ohm-metre, or 1.77 × 10-6 ohm-centimetre. A copper wire has a diameter 0.5 mm and resistivity of 1.6 X 10-8 Ωm. It is the property of the material that opposes the flow of charge or the flow of electric current. What will be the length of this wire to make its resistance 10 Ω? Question 5. Resistivity of a conductor is defined as resistance of the conductor of unit length and unit area of cross-section. Q7. Wood is considered as a high-insulator but this varies depending upon the amount of moisture present in it. HOTS Questions for Class 10 Science Chapter 12 Electricity. Resistivity is the characteristic property of the material by which it resists the amount of current through it.What is the SI Unit of resistivity?SI Unit of resistivity is ohm meter.Explanation.We know that,R = ρ (l/A)Therefore,ρ = R (A/l)= ohm × m2/m= ohm × mTherefore, unit of rho is ohm meter.Not Filed Under: Class 10, Electricity Tagged With: area of cross section, cause of resistance, connecting wires, filament of an electric bulb, length, nichrome, resistance, resistivity. ... Q6. Find the resistance of a hollow cylindrical pipe of length 1m whose inner and outer radii are 10cm and 20 cm respectively. The unit of resistivity is ohm meter. If, l = 1 m and a = 1 m2 Then R = ρ …. The lower the resistivity, the more readily the material permits the flow of electric charge. At the other extreme, electrical insulators have resistivities in the range 10 1 2 to 10 2 0 ohm-metres. Assume that the cylindrical pipe is made of a material of resistivity 2 x 10-8 ohm m. Conductivity is a measure of how well a material conducts an electric current. The Questions and Answers of What is electrical resistivity ? How much does the resistance change if the diameter is doubled? If the answer is not available please wait for a while and a community member will probably answer this soon.