Question

Assertion  :   In Hertz experiment, the electric vector of radiation produced by the source gap is parallel to the gap.

Reason      : Production of sparks between the detector gap is maximum when it is placed perpendicular to the source gap.

(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.

Answer

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

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

An electron is accelerated through a potential difference of 200 volts. If e/m for the electron be 1.6   coulomb/kg, the velocity acquired by the electron will be

(a) 8  

(b) 8 

(c) 5.9  

(d) 5.9  

The self inductance of a straight conductor is.

After 1α and 2β emissions

(a) Mass number reduces by 3

(b) Mass number reduces by 4

(c) Mass number reduces by 6

(d) Atomic number remains unchanged

The critical angle for diamond (refractive index = 2) is

(a) About 20°

(b) 60°

(c) 45°     

(d) 30°

Mark the correct option in impure spectrum:
Two uniform solid spheres having unequal masses and unequal radii are released from rest from the same height on a rough incline. If the spheres roll without slipping:
  1. The heavier sphere reaches the bottom first.
  2. The bigger sphere reaches the bottom first.
  3. The two spheres reach the bottom together.
  4. The information given is not sufficient to tell which sphere will reach the bottom first.

A circular loop of radius R carrying current I lies in x-y plane with its centre at origin. The total magnetic flux through x-y plane is

(a) Directly proportional to I

(b) Directly proportional to R

(c) Directly proportional to  

(d) Zero

Assertion  :  A narrow pulse of light is sent through a medium. The pulse will  retain its shape as it travels through the medium.

Reason      : A narrow pulse is made of harmonic waves with a large range of wavelengths.

(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 assertion is false but reason is true.

A 10 m long wire of 20W resistance is connected with a battery of 3 volt e.m.f. (negligible internal resistance) and a 10 W resistance is joined to it is series. Potential gradient along wire in volt per meter is

(a) 0.02   

(b) 0.3

(c) 0.2

(d) 1.3

Consider the following statements:
  1. An emf can be induced by moving a conductor in a magnetic field.
  2. An emf can be induced by changing the magnetic field.
  1. Both A and B are true.
  2. A is true but B is false.
  3. B is true but A is false.
  4. Both A and B are false.