152170
A certain electrical conductor has a square cross-section, $2.0 \mathrm{~mm}$ on side, and is $12 \mathrm{~m}$ long. The resistance between its ends is $0.072 \Omega$. The resistivity of its material is equal to :
1 $2.4 \times 10^{-6} \Omega \mathrm{m}$
2 $1.2 \times 10^{-6} \Omega \mathrm{m}$
3 $1.2 \times 10^{-8} \Omega \mathrm{m}$
4 $2.4 \times 10^{-8} \Omega \mathrm{m}$
Explanation:
D Given that, $\mathrm{R}=0.072 \Omega$ $\mathrm{A}=(2 \times 2) \mathrm{mm}^{2}=4 \times 10^{-6} \mathrm{~m}^{2}$ $l=12 \mathrm{~m} \text {. }$ We know that, Resistance of a conductor is given by, $\mathrm{R} =\rho \frac{l}{\mathrm{~A}}$ $\rho =\frac{\mathrm{RA}}{l}$ $\rho =\frac{0.072 \times 4 \times 10^{-6}}{12}$ $\rho =2.4 \times 10^{-8} \Omega \mathrm{m}$
BCECE-2006
Current Electricity
152156
The heating element of a heater should be made of material which should have
1 high resistivity and high melting point
2 high resistivity and low melting point
3 low resistivity and low melting point
4 low resistivity and high melting point
Explanation:
A We know that, Resistance $(\mathrm{R})=\frac{\rho l}{\mathrm{~A}}$ $\rho=\frac{\mathrm{RA}}{l}$ So, we can say that the heating elements resistivity is directly proportional to its resistance. High resistivity is the desirable property of a heating element. Therefore, the heating element of a heater should be made of material which should have high resistivity and high melting point.
J and K CET- 1998
Current Electricity
152142
When the temperature of a metallic resistor is increased, the product of its resistivity and conductivity
1 increases
2 decreases
3 remains constant
4 may increases of decrease
Explanation:
C We know that, $\text { Resistivity }(\rho)=\frac{1}{\operatorname{Conductivity}(\sigma)}$ $\because$ The product of resistivity and conductivity is constant. Resistivity $\times$ Conductivity $=$ Constant. Conductivity is measure of how easily electricity flows, electrical resistivity measure how much a material resists the flow of electricity.
CG PET- 2012
Current Electricity
152149
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
1 Drift speed
2 Resistivity
3 Resistance
4 Number of free electrons
Explanation:
D When resistor connected to a battery is heated due to the current then resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature. But number of free electrons in a conductor do not change even if its temperature changes.
BITSAT-2010
Current Electricity
152151
Fractional increase in resistivity per unit increase in temperature is defined as
1 resistivity
2 temperature coefficient of resistivity
3 conductivity
4 drift velocity
Explanation:
B Fractional increase in resistivity per unit increase in temperature is defined as temperature coefficient of resistivity. $\mathrm{R}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})$ Where, $\alpha \rightarrow$ Temperature coefficient of resistivity
152170
A certain electrical conductor has a square cross-section, $2.0 \mathrm{~mm}$ on side, and is $12 \mathrm{~m}$ long. The resistance between its ends is $0.072 \Omega$. The resistivity of its material is equal to :
1 $2.4 \times 10^{-6} \Omega \mathrm{m}$
2 $1.2 \times 10^{-6} \Omega \mathrm{m}$
3 $1.2 \times 10^{-8} \Omega \mathrm{m}$
4 $2.4 \times 10^{-8} \Omega \mathrm{m}$
Explanation:
D Given that, $\mathrm{R}=0.072 \Omega$ $\mathrm{A}=(2 \times 2) \mathrm{mm}^{2}=4 \times 10^{-6} \mathrm{~m}^{2}$ $l=12 \mathrm{~m} \text {. }$ We know that, Resistance of a conductor is given by, $\mathrm{R} =\rho \frac{l}{\mathrm{~A}}$ $\rho =\frac{\mathrm{RA}}{l}$ $\rho =\frac{0.072 \times 4 \times 10^{-6}}{12}$ $\rho =2.4 \times 10^{-8} \Omega \mathrm{m}$
BCECE-2006
Current Electricity
152156
The heating element of a heater should be made of material which should have
1 high resistivity and high melting point
2 high resistivity and low melting point
3 low resistivity and low melting point
4 low resistivity and high melting point
Explanation:
A We know that, Resistance $(\mathrm{R})=\frac{\rho l}{\mathrm{~A}}$ $\rho=\frac{\mathrm{RA}}{l}$ So, we can say that the heating elements resistivity is directly proportional to its resistance. High resistivity is the desirable property of a heating element. Therefore, the heating element of a heater should be made of material which should have high resistivity and high melting point.
J and K CET- 1998
Current Electricity
152142
When the temperature of a metallic resistor is increased, the product of its resistivity and conductivity
1 increases
2 decreases
3 remains constant
4 may increases of decrease
Explanation:
C We know that, $\text { Resistivity }(\rho)=\frac{1}{\operatorname{Conductivity}(\sigma)}$ $\because$ The product of resistivity and conductivity is constant. Resistivity $\times$ Conductivity $=$ Constant. Conductivity is measure of how easily electricity flows, electrical resistivity measure how much a material resists the flow of electricity.
CG PET- 2012
Current Electricity
152149
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
1 Drift speed
2 Resistivity
3 Resistance
4 Number of free electrons
Explanation:
D When resistor connected to a battery is heated due to the current then resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature. But number of free electrons in a conductor do not change even if its temperature changes.
BITSAT-2010
Current Electricity
152151
Fractional increase in resistivity per unit increase in temperature is defined as
1 resistivity
2 temperature coefficient of resistivity
3 conductivity
4 drift velocity
Explanation:
B Fractional increase in resistivity per unit increase in temperature is defined as temperature coefficient of resistivity. $\mathrm{R}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})$ Where, $\alpha \rightarrow$ Temperature coefficient of resistivity
152170
A certain electrical conductor has a square cross-section, $2.0 \mathrm{~mm}$ on side, and is $12 \mathrm{~m}$ long. The resistance between its ends is $0.072 \Omega$. The resistivity of its material is equal to :
1 $2.4 \times 10^{-6} \Omega \mathrm{m}$
2 $1.2 \times 10^{-6} \Omega \mathrm{m}$
3 $1.2 \times 10^{-8} \Omega \mathrm{m}$
4 $2.4 \times 10^{-8} \Omega \mathrm{m}$
Explanation:
D Given that, $\mathrm{R}=0.072 \Omega$ $\mathrm{A}=(2 \times 2) \mathrm{mm}^{2}=4 \times 10^{-6} \mathrm{~m}^{2}$ $l=12 \mathrm{~m} \text {. }$ We know that, Resistance of a conductor is given by, $\mathrm{R} =\rho \frac{l}{\mathrm{~A}}$ $\rho =\frac{\mathrm{RA}}{l}$ $\rho =\frac{0.072 \times 4 \times 10^{-6}}{12}$ $\rho =2.4 \times 10^{-8} \Omega \mathrm{m}$
BCECE-2006
Current Electricity
152156
The heating element of a heater should be made of material which should have
1 high resistivity and high melting point
2 high resistivity and low melting point
3 low resistivity and low melting point
4 low resistivity and high melting point
Explanation:
A We know that, Resistance $(\mathrm{R})=\frac{\rho l}{\mathrm{~A}}$ $\rho=\frac{\mathrm{RA}}{l}$ So, we can say that the heating elements resistivity is directly proportional to its resistance. High resistivity is the desirable property of a heating element. Therefore, the heating element of a heater should be made of material which should have high resistivity and high melting point.
J and K CET- 1998
Current Electricity
152142
When the temperature of a metallic resistor is increased, the product of its resistivity and conductivity
1 increases
2 decreases
3 remains constant
4 may increases of decrease
Explanation:
C We know that, $\text { Resistivity }(\rho)=\frac{1}{\operatorname{Conductivity}(\sigma)}$ $\because$ The product of resistivity and conductivity is constant. Resistivity $\times$ Conductivity $=$ Constant. Conductivity is measure of how easily electricity flows, electrical resistivity measure how much a material resists the flow of electricity.
CG PET- 2012
Current Electricity
152149
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
1 Drift speed
2 Resistivity
3 Resistance
4 Number of free electrons
Explanation:
D When resistor connected to a battery is heated due to the current then resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature. But number of free electrons in a conductor do not change even if its temperature changes.
BITSAT-2010
Current Electricity
152151
Fractional increase in resistivity per unit increase in temperature is defined as
1 resistivity
2 temperature coefficient of resistivity
3 conductivity
4 drift velocity
Explanation:
B Fractional increase in resistivity per unit increase in temperature is defined as temperature coefficient of resistivity. $\mathrm{R}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})$ Where, $\alpha \rightarrow$ Temperature coefficient of resistivity
152170
A certain electrical conductor has a square cross-section, $2.0 \mathrm{~mm}$ on side, and is $12 \mathrm{~m}$ long. The resistance between its ends is $0.072 \Omega$. The resistivity of its material is equal to :
1 $2.4 \times 10^{-6} \Omega \mathrm{m}$
2 $1.2 \times 10^{-6} \Omega \mathrm{m}$
3 $1.2 \times 10^{-8} \Omega \mathrm{m}$
4 $2.4 \times 10^{-8} \Omega \mathrm{m}$
Explanation:
D Given that, $\mathrm{R}=0.072 \Omega$ $\mathrm{A}=(2 \times 2) \mathrm{mm}^{2}=4 \times 10^{-6} \mathrm{~m}^{2}$ $l=12 \mathrm{~m} \text {. }$ We know that, Resistance of a conductor is given by, $\mathrm{R} =\rho \frac{l}{\mathrm{~A}}$ $\rho =\frac{\mathrm{RA}}{l}$ $\rho =\frac{0.072 \times 4 \times 10^{-6}}{12}$ $\rho =2.4 \times 10^{-8} \Omega \mathrm{m}$
BCECE-2006
Current Electricity
152156
The heating element of a heater should be made of material which should have
1 high resistivity and high melting point
2 high resistivity and low melting point
3 low resistivity and low melting point
4 low resistivity and high melting point
Explanation:
A We know that, Resistance $(\mathrm{R})=\frac{\rho l}{\mathrm{~A}}$ $\rho=\frac{\mathrm{RA}}{l}$ So, we can say that the heating elements resistivity is directly proportional to its resistance. High resistivity is the desirable property of a heating element. Therefore, the heating element of a heater should be made of material which should have high resistivity and high melting point.
J and K CET- 1998
Current Electricity
152142
When the temperature of a metallic resistor is increased, the product of its resistivity and conductivity
1 increases
2 decreases
3 remains constant
4 may increases of decrease
Explanation:
C We know that, $\text { Resistivity }(\rho)=\frac{1}{\operatorname{Conductivity}(\sigma)}$ $\because$ The product of resistivity and conductivity is constant. Resistivity $\times$ Conductivity $=$ Constant. Conductivity is measure of how easily electricity flows, electrical resistivity measure how much a material resists the flow of electricity.
CG PET- 2012
Current Electricity
152149
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
1 Drift speed
2 Resistivity
3 Resistance
4 Number of free electrons
Explanation:
D When resistor connected to a battery is heated due to the current then resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature. But number of free electrons in a conductor do not change even if its temperature changes.
BITSAT-2010
Current Electricity
152151
Fractional increase in resistivity per unit increase in temperature is defined as
1 resistivity
2 temperature coefficient of resistivity
3 conductivity
4 drift velocity
Explanation:
B Fractional increase in resistivity per unit increase in temperature is defined as temperature coefficient of resistivity. $\mathrm{R}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})$ Where, $\alpha \rightarrow$ Temperature coefficient of resistivity
152170
A certain electrical conductor has a square cross-section, $2.0 \mathrm{~mm}$ on side, and is $12 \mathrm{~m}$ long. The resistance between its ends is $0.072 \Omega$. The resistivity of its material is equal to :
1 $2.4 \times 10^{-6} \Omega \mathrm{m}$
2 $1.2 \times 10^{-6} \Omega \mathrm{m}$
3 $1.2 \times 10^{-8} \Omega \mathrm{m}$
4 $2.4 \times 10^{-8} \Omega \mathrm{m}$
Explanation:
D Given that, $\mathrm{R}=0.072 \Omega$ $\mathrm{A}=(2 \times 2) \mathrm{mm}^{2}=4 \times 10^{-6} \mathrm{~m}^{2}$ $l=12 \mathrm{~m} \text {. }$ We know that, Resistance of a conductor is given by, $\mathrm{R} =\rho \frac{l}{\mathrm{~A}}$ $\rho =\frac{\mathrm{RA}}{l}$ $\rho =\frac{0.072 \times 4 \times 10^{-6}}{12}$ $\rho =2.4 \times 10^{-8} \Omega \mathrm{m}$
BCECE-2006
Current Electricity
152156
The heating element of a heater should be made of material which should have
1 high resistivity and high melting point
2 high resistivity and low melting point
3 low resistivity and low melting point
4 low resistivity and high melting point
Explanation:
A We know that, Resistance $(\mathrm{R})=\frac{\rho l}{\mathrm{~A}}$ $\rho=\frac{\mathrm{RA}}{l}$ So, we can say that the heating elements resistivity is directly proportional to its resistance. High resistivity is the desirable property of a heating element. Therefore, the heating element of a heater should be made of material which should have high resistivity and high melting point.
J and K CET- 1998
Current Electricity
152142
When the temperature of a metallic resistor is increased, the product of its resistivity and conductivity
1 increases
2 decreases
3 remains constant
4 may increases of decrease
Explanation:
C We know that, $\text { Resistivity }(\rho)=\frac{1}{\operatorname{Conductivity}(\sigma)}$ $\because$ The product of resistivity and conductivity is constant. Resistivity $\times$ Conductivity $=$ Constant. Conductivity is measure of how easily electricity flows, electrical resistivity measure how much a material resists the flow of electricity.
CG PET- 2012
Current Electricity
152149
Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
1 Drift speed
2 Resistivity
3 Resistance
4 Number of free electrons
Explanation:
D When resistor connected to a battery is heated due to the current then resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature. But number of free electrons in a conductor do not change even if its temperature changes.
BITSAT-2010
Current Electricity
152151
Fractional increase in resistivity per unit increase in temperature is defined as
1 resistivity
2 temperature coefficient of resistivity
3 conductivity
4 drift velocity
Explanation:
B Fractional increase in resistivity per unit increase in temperature is defined as temperature coefficient of resistivity. $\mathrm{R}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})$ Where, $\alpha \rightarrow$ Temperature coefficient of resistivity
