(i) Resistivity of iron = 10.0 x 10-8 Ω m Resistivity of mercury = 94.0 x 10-8 Ω m. Thus iron is a better conductor because it has lower resistivity than mercury. (ii) Because silver has the lowest resistivity (= 1.60 x 10-8 Ω m), therefore silver is the best conductor.
(i) Resistivity of iron = 10.0 x 10-8 Ω m
Resistivity of mercury = 94.0 x 10-8 Ω m.
Thus iron is a better conductor because it has lower resistivity than mercury.
(ii) Because silver has the lowest resistivity (= 1.60 x 10-8 Ω m), therefore silver is the best conductor.
The coils of electric toasters, electric irons and other heating devices are made of an alloy rather than a pure metal because (i) the resistivity of an alloy is much higher than that of a pure metal, and (ii) an alloy does not undergo oxidation (or burn) easily even at high temperature, when it isRead more
The coils of electric toasters, electric irons and other heating devices are made of an alloy rather than a pure metal because
(i) the resistivity of an alloy is much higher than that of a pure metal, and
(ii) an alloy does not undergo oxidation (or burn) easily even at high temperature, when it is red hot.
When potential difference is halved, the current through the component also decreases to half of its initial value. This is according to ohm’s law i.e., V ∝ I.
When potential difference is halved, the current through the component also decreases to half of its initial value. This is according to ohm’s law i.e., V ∝ I.
The current will flow more easily through a thick wire than a thin wire of the same material. Larger the area of cross-section of a conductor, more is the ease with which the electrons can move through the conductor. Therefore, smaller is the resistance of the conductor.
The current will flow more easily through a thick wire than a thin wire of the same material. Larger the area of cross-section of a conductor, more is the ease with which the electrons can move through the conductor. Therefore, smaller is the resistance of the conductor.
The potential difference between two points is said to be 1 volt if 1 joule of work is done in moving 1 coulomb of electric charge from one point to the other.
The potential difference between two points is said to be 1 volt if 1 joule of work is done in moving 1 coulomb of electric charge from one point to the other.
Unit of current is ampere. If one coulomb of charge flows through any section of a conductor in one second then the current through it is said to be one ampere. I = Qt or 1 A = I C s-1
Unit of current is ampere. If one coulomb of charge flows through any section of a conductor in one second then the current through it is said to be one ampere.
I = Qt or 1 A = I C s-1
Use the data in Table 12.2 to answer the following –
(i) Resistivity of iron = 10.0 x 10-8 Ω m Resistivity of mercury = 94.0 x 10-8 Ω m. Thus iron is a better conductor because it has lower resistivity than mercury. (ii) Because silver has the lowest resistivity (= 1.60 x 10-8 Ω m), therefore silver is the best conductor.
(i) Resistivity of iron = 10.0 x 10-8 Ω m
See lessResistivity of mercury = 94.0 x 10-8 Ω m.
Thus iron is a better conductor because it has lower resistivity than mercury.
(ii) Because silver has the lowest resistivity (= 1.60 x 10-8 Ω m), therefore silver is the best conductor.
Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?
The coils of electric toasters, electric irons and other heating devices are made of an alloy rather than a pure metal because (i) the resistivity of an alloy is much higher than that of a pure metal, and (ii) an alloy does not undergo oxidation (or burn) easily even at high temperature, when it isRead more
The coils of electric toasters, electric irons and other heating devices are made of an alloy rather than a pure metal because
(i) the resistivity of an alloy is much higher than that of a pure metal, and
(ii) an alloy does not undergo oxidation (or burn) easily even at high temperature, when it is red hot.
See lessLet the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?
When potential difference is halved, the current through the component also decreases to half of its initial value. This is according to ohm’s law i.e., V ∝ I.
When potential difference is halved, the current through the component also decreases to half of its initial value. This is according to ohm’s law i.e., V ∝ I.
See lessWill current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
The current will flow more easily through a thick wire than a thin wire of the same material. Larger the area of cross-section of a conductor, more is the ease with which the electrons can move through the conductor. Therefore, smaller is the resistance of the conductor.
The current will flow more easily through a thick wire than a thin wire of the same material. Larger the area of cross-section of a conductor, more is the ease with which the electrons can move through the conductor. Therefore, smaller is the resistance of the conductor.
See lessOn what factors does the resistance of a conductor depend?
The resistance of a conductor depends (i) on its length (ii) on its area of cross-section and (iii) on the nature of its material.
The resistance of a conductor depends
(i) on its length
(ii) on its area of cross-section and
(iii) on the nature of its material.
See lessHow much energy is given to each coulomb of charge passing through a 6 V battery?
Energy given by battery = charge x potential difference or W = QV = 1C X 6V = 6J.
Energy given by battery = charge x potential difference
See lessor W = QV = 1C X 6V = 6J.
What is meant by saying that the potential difference between two points is 1 V?
The potential difference between two points is said to be 1 volt if 1 joule of work is done in moving 1 coulomb of electric charge from one point to the other.
The potential difference between two points is said to be 1 volt if 1 joule of work is done in moving 1 coulomb of electric charge from one point to the other.
See lessName a device that helps to maintain a potential difference across a conductor.
A battery.
A battery.
See lessCalculate the number of electrons constituting one coulomb of charge.
Charge on one electron, e = 1.6 x 10-19 C Total charge, Q = 1 C Number of electrons, n= Q/e = 1C/1.6x10raise to power-19 = 6.25 x 1018
Charge on one electron, e = 1.6 x 10-19 C
See lessTotal charge, Q = 1 C
Number of electrons, n= Q/e = 1C/1.6x10raise to power-19 = 6.25 x 1018
Define the unit of current.
Unit of current is ampere. If one coulomb of charge flows through any section of a conductor in one second then the current through it is said to be one ampere. I = Qt or 1 A = I C s-1
Unit of current is ampere. If one coulomb of charge flows through any section of a conductor in one second then the current through it is said to be one ampere.
See lessI = Qt or 1 A = I C s-1