MCQ
For small currents, ‘X’ obeys Ohm’s law. But when large currents are passed through the same conductor, it deviates from ohmic behaviour. Identify X.
  • A
    Metallic conductor.
  • B
    Gallium arsenide.
  • C
    Thyristor.
  • D
    p-n junction diode.

Answer

  1. Metallic conductor.

Explanation:

‘X’ is a metallic conductor. For small currents, it obeys Ohms’s law and its V-I graph is a straight line. But when large currents are passed through the same conductor, it gets heated up and its resistance increases. It no longer obeys Ohm’s law at higher currents.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Through which character we can distinguish the light waves from sound waves

(a) Interference

(b) Refraction

(c) Polarisation

(d) Reflection

The graph between the de Broglie wavelength and the momentum of a photon is a:

A 60 watt bulb is hung over the center of a table 4 m × 4 m at a height of 3 m. The ratio of the intensities of illumination at a point on the centre of the edge and on the corner of the table is

(a)  

(b) 2 / 1

(c) 17 / 13

(d)  5 / 4

A galvanometer is converted into ammeter by adding :

The current in a coil changes from 4 ampere to zero in 0.1 s. If the average e.m.f. induced is 100 volt, what is the self inductance of the coil

(a) 2.5 H

(b) 25 H

(c) 400 H

(d) 40 H

Assertion   :   Free electron always keep on moving in a conductor even then no magnetic force act on them in magnetic field unless a current is passed through it.

Reason       : The average velocity of free electron is zero.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

Assertion   :   Photoelectric effect demonstrates the wave nature of light.

Reason       : The number of photoelectrons is proportional to the frequency of light.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

The ratio of intensities of two waves are given by 4 : 1. The ratio of the amplitudes of the two waves is

(a) 2 : 1

(b) 1 : 2

(c) 4 : 1

(d) 1 : 4

Light from a hydrogen discharge tube is incident on the cathode of a photoelectric cell the work function of the cathode surface is 4.2 eV. In order to reduce the photo-current to zero the voltage of the anode relative to the cathode must be made

(a) – 4.2 V

(b) – 9.4 V

(c) – 17.8 V

(d) +9.4 V

When the distance between the charged particles is halved, the force between them becomes

(a) One-fourth

(b) Half

(c) Double

(d) Four times