Two copper wires, of 1 m and 9 m respectively, have same resistance. Find their diameters in ratio.

The electrical resistance an electrical conductor has is known as the resistance to the passage of electric current via it.

A wire’s resistance is inversely proportional to area of the wire’s cross-section. It is also directly proportional to the wire’s length.
In case the diameter of wire increases, while length of the wire decreases, then the resistance of the wire lowers. Thus, as the diameter of the wire decreases while length of the wire increases, then the resistance of the wire increases.

The resistance of the conductor can be expressed as:

R = ρ l/A

Herein, the wire is 9 times longer than the first one. The resistance simultaneously increases as the length expands. Since the diameter of the wire is inversely linked to the resistance, it can be increased in order to maintain equivalent resistance. Now, since the area of the cross-section is considered proportional to the diameter, the resistance will be constant when diameter of the wire will be increased by three times.

Thus, their diameters will be in the 1:3 ratio.

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Two copper wires, of 1 m and 9 m respectively, have same resistance. Find their diameters in ratio.

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Two small identical metallic balls having charges \( q \) and \( -2q \) are kept far at a separation \( r \). They are brought in contact and then separated at distance \( \frac{r}{2} \). Compared to the initial force \( F \), they will now:

4.
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5.
The magnetic field in a plane electromagnetic wave travelling in glass (\( n = 1.5 \)) is given by \[ B_y = (2 \times 10^{-7} \text{ T}) \sin(\alpha x + 1.5 \times 10^{11} t) \] where \( x \) is in metres and \( t \) is in seconds. The value of \( \alpha \) is:

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Two copper wires, of 1 m and 9 m respectively, have same resistance. Find their diameters in ratio.

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CBSE CLASS XII Related Questions

2.Two small identical metallic balls having charges \( q \) and \( -2q \) are kept far at a separation \( r \). They are brought in contact and then separated at distance \( \frac{r}{2} \). Compared to the initial force \( F \), they will now:

4.The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

5.The magnetic field in a plane electromagnetic wave travelling in glass (\( n = 1.5 \)) is given by \[ B_y = (2 \times 10^{-7} \text{ T}) \sin(\alpha x + 1.5 \times 10^{11} t) \] where \( x \) is in metres and \( t \) is in seconds. The value of \( \alpha \) is:

6.In a Young's double-slit experiment, two waves each of intensity I superpose each other and produce an interference pattern. Prove that the resultant intensities at maxima and minima are 4I and zero respectively.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

2.
Two small identical metallic balls having charges \( q \) and \( -2q \) are kept far at a separation \( r \). They are brought in contact and then separated at distance \( \frac{r}{2} \). Compared to the initial force \( F \), they will now:

4.
The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

5.
The magnetic field in a plane electromagnetic wave travelling in glass (\( n = 1.5 \)) is given by \[ B_y = (2 \times 10^{-7} \text{ T}) \sin(\alpha x + 1.5 \times 10^{11} t) \] where \( x \) is in metres and \( t \) is in seconds. The value of \( \alpha \) is:

6.
In a Young's double-slit experiment, two waves each of intensity I superpose each other and produce an interference pattern. Prove that the resultant intensities at maxima and minima are 4I and zero respectively.