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

Assertion : A current flows in a conductor only when there is an electric field within the conductor. Reason : The drift velocity of electron in presence of electric field decreases.

Options

  1. AIf both assertion and reason are true and reason is the correct explanation of assertion.
  2. BIf both assertion and reason are true but reason is not the correct explanation of assertion.
  3. CIf assertion is true but reason is false.
  4. DIf both assertion and reason are false.

Correct answer

C. If assertion is true but reason is false.

Step-by-step solution

In the absence of external electric field, the free electrons move randomly in the conductor, so their drift velocity is zero and therefore there is no current in the conductor. In the presence of electric field, each electron in the conductor experiences a force in a direction opposite to the electric field. Now the free electrons are drifted from negative end to the positive end of the conductor and hence a current starts to flow in the conductor.

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