Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsCurrent Electricity

If the current in resistance of uniform cross section is doubled then, (assume temperature to be approximately constant). (A) the current density is doubled (B) the conduction electron density is doubled (C) the mean time between collision is constant (D) the electron drift speed is doubled

Options

  1. AA, C, D
  2. BB, C, D
  3. CA, B, C
  4. DA, B, C, D

Correct answer

A. A, C, D

Step-by-step solution

- (A) The current density is doubled: - Current density (J ) is given by (J= I A ), where (I ) is the current and (A ) is the cross-sectional area. If the current (I ) is doubled and the cross-sectional area (A ) remains constant, then the current density will also double. This statement is true. - (B) The conduction electron density is doubled: - The conduction electron density refers to the number of free electrons per unit volume in the material, which is a property of the material and does not change with the c

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