Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET2018PhysicsCurrent ElectricityActual

A current i is flowing through the wire of diameter (d) having drift velocity of electrons v _ d in it. What will be new drift velocity when diameter of wire is made d / 4 ?

Options

  1. A4 v_d
  2. Bv_d 4
  3. C16 v_d
  4. Dv_d 16

Correct answer

C. 16 v_d

Step-by-step solution

Current, I = nAev _ d or v _ d 1 ~A If diameter of wire is d 4 , then area will be A 16 , so new drift velocity =16 v_d .

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

A potentiometer wire of 400 cm length has a resistance of 20 . It is connected in series with a resistance of 15 and a accumulator of EMF 6 V (negligible internal resistance). The 2026In the following figure current I equal to 2026The range of voltmeter is 10 V and its resistance is 50 . To convert it to a voltmeter of range 15 V , how much resistance is to be added? 2026When a galvanometer is shunted with a 2 resistance, the deflection is reduced to one-fourth. If the galvanometer is further shunted with a 1 resistance, the further reduction in de 2026A galvanometer can be converted into a voltmeter of certain range by connecting a resistance of 990 in series with it. When the resistance of 480 is connected in series, the range 2026A resistance is to be measured using a meter bridge; the student chooses the standard resistance R to be 100 . The student finds the null point at l₁=16 cm. To get the null point n 2026Which of the following statements is FALSE? A. In a balanced Wheatstone bridge, if the cell and the galvanometer are exchanged, the null point is disturbed. B. A rheostat can be us 2026A potentiometer wire has length 4 m and resistance 8 . The resistance that must be connected in series with the wire and the driving battery of e.m.f. 2 V, so as to get a potential 2026 Full Current Electricity list All NEET PYQs