Current Electricity — Physics STD 12 Science — Question

If cathode rays are projected at right angles to a magnetic field, their trajectory is (a) Ellipse(b) Circle(c) Parabola(d) None of these

The ratio of intensity of magnetisation and magnetising field is called:

The relaxation time in conductors:

The phase difference between incident wave and reflected wave is 180° when light ray(a) Enters into glass from air(b) Enters into air from glass(c) Enters into glass from diamond(d)  Enters into water from glass

Photoelectric effect was discovered by:

Assertion  :   Electric lines of force cross each other.
Reason      : Electric field at a point superimpose to give one resultant electric field.(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.

Permanent magnets are made from:

The process of sharing the charges with the earth is called as:

Which of the following statement is true  (a) Velocity of light is constant in all media  (b) Velocity of light in vacuum is maximum
  (c) Velocity of light is same in all reference frames(d) Laws of nature have identical form in all reference frames

P-type semiconductor is formed when
A. As impurity is mixed in Si                                                                         B. Al impurity is mixed in Si
C. B impurity is mixed in Ge                                                                         D. P impurity is mixed in Ge(a) A and C(b) A and D(c) B and C(d) B and D