Advertisements
Advertisements
Question
Calculate the electric field in a copper wire of cross-sectional area 2.0 mm2 carrying a current of 1 A.
The resistivity of copper = 1.7 × 10–8 Ω m
Advertisements
Solution
Given:-
Area of cross-section, A = 2 × 10–6 m2
Current through the wire, i = 1 A
Resistivity of copper, ρ = 1.7 × 10–8 Ωm
Resistance of a wire,
\[R = \rho\frac{l}{A}\]
Also from Ohm's Law, voltage across a wire,
\[V = iR = \frac{i\rho l}{A}\]
The electric field of the wire,
\[E = \frac{V}{l}\]
Now:
`R = (fl)/A`
`= (1.7xx10^(-8)xxl)/(2xx10^-6)`
`V = iR = (1 xx1.7xx10^-8xxl)/(2xx10^-6)`
`E = (dV)/(dL) = V/l`
`= (1.7xx10^-8)/(2xx10^-6`
`= 1.7/2xx10^-2`
`= 17xx10^-3`
`= 8.5xx10^-3`mv/m.
APPEARS IN
RELATED QUESTIONS
If the potential difference across the ends of a conductor is 220 V and the resistance of the conductor is 44 Ω (ohm), then the current flowing through is _________.
- 0.2 A
- 0.5 A
- 2 A
- 5 A
Write the SI unit of resistivity
Name the unit of electrical resistance and give its symbol.
The unit of electrical resistance is:
(a) ampere
(b) volt
(c) coulomb
(d) ohm
The graph between V and I for a conductor is a straight line passing through the origin.
What should remain constant in a statement of this law?
- Draw a V-I graph for a conductor obeying Ohm’s law.
- What does the slope of V–I graph for a conductor represent?
Fig. represents the circuit used for the verification of Ohm's law. Label the parts from A to F. state the function of each.
What is meant by the drift speed of free electrons?
Rewrite the following statement by selecting the correct option.
The S.I. unit of resistance is __________.
State the relation correlating the electric current flowing in a conductor and the voltage applied across it. Also, draw a graph to show this relationship.
Define ampere and volt with respect to Ohm’s law.
Answer the following question.
Distinguish between Ohmic and non-ohmic substances; explain with the help of example.
An electronics hobbyist is building a radio which requires 150 Ω in her circuit, but she has only 220 Ω, 79 Ω, and 92 Ω resistors available. How can she connect the available resistors to get the desired value of resistance?
The variable resistance is called ____________.
A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances R1, R2 and R3 respectively. Which of the following is hue?
State Ohm’s law? How can it be verified experimentally? Does it hold good under all conditions? Comment.
The heat produced by a 100 w heater in 2 minute is equal to
A metal rod of length 10 cm and a rectangular cross-section of 1 cm × `1/2` cm is connected to a battery across opposite faces. The resistance will be ______.
Two conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 1 mm. Conductor B is a hollow tube of outer diameter 2 mm and inner diameter 1 mm. Find the ratio of resistance RA to RB.
