Question

Drift speed of electrons, when 1.5A of current flows in a copper wire of cross section 5mm², is v. If the electron density in copper is 9×10²⁸/m³ the value of v in mm/s is close to (Take charge of electron to be =1.6×10⁻¹⁹C)

Answer 1

The drift velocity v of electrons can be calculated using the formula I = nqAvd. After converting the given values and solving for vd, we can obtain the drift velocity in m/s and then convert it to mm/s by multiplying by 1000.

Step-by-step explanation:

To calculate the drift speed v of electrons when a current of 1.5A flows through a copper wire with a cross-sectional area of 5mm², and given the electron density in copper is 9×10²⁸/m³ and the charge of an electron 1.6×10⁻¹⁹ C, we can use the formula I = nqAvd. Here, I is the current, n is the electron density, q is the charge of each electron, A is the cross-sectional area of the wire in m², and vd is the drift velocity we're trying to find.

First, convert the area from mm² to m²: 5 mm² = 5 × 10⁻⁶ m².

Now rearrange the formula to solve for drift velocity: vd = I/(nqA). Substituting in the values, we get vd = 1.5/(9×10²⁸×1.6×10⁻¹⁹×5×10⁻⁶), giving us the drift speed in m/s. To find the answer in mm/s, multiply this result by 1000.