Advertisements
Advertisements
प्रश्न
A cylindrical conductor of length l and uniform area of cross section A has resistance R. Another conductor of length 2l and resistance R of the same material has area of cross section
पर्याय
A/2
3A/2
2A
3A
उत्तर
2A
Explanation -
Let the resistivity of the material be ρ
Resistance (R) of the first cylindrical conductor = `(rho"l")/"A"`
where, l = length of conductor
A = area of cross section
Now, another cylindrical conductor has double length but same resistance.
Let its area of cross section be A'
Its resistance (R') will be = `(rho xx 2"l")/"A"^"'"`
Since resistance is same
R = R'
`(rho xx "l")/"A" = (rho xx 2"l")/"A"^"'"`
Solving it, we get A' = 2A
APPEARS IN
संबंधित प्रश्न
Which of the following statements correctly defines a volt?
(a) a volt is a joule per ampere.
(b) a volt is a joule per coulomb.
What is the SI unit of potential difference?
The values of potential difference V applies across a resistor and the corresponding values of current I flowing in the resistor are given below:
| Potential differences, V (in volts) | : | 2.5 | 5.0 | 10.0 | 15.0 | 20.0 | 25.0 |
| Current, I (in amperes) | : | 0.1 | 0.2 | 0.4 | 0.6 | 0.8 | 1.0 |
The V-I graph for a series combination and for a parallel combination of two resistors is shown in Fig – 8.38. Which of the two, A or B, represents the parallel combination? Give a reason for your answer.
Water in the waterfall flows from a higher level to the lower level because of ____________.
A current of 100 mA. flows through a wire. The charge on an electron is 1.6 × 10-19 C. Find the number of electrons passing per second through the cross-section of the conductor.
If P and V are the power and potential of device, the power consumed with a supply potential V1 is:
Electric potential is a ____________.
A negative charge will move from ______ to ______ potential.
