Moving Charges and Magnetism — Physics STD 12 Science — Question

Which of the following is wrong statement(a) An emf can be induced between the ends of a straight conductor by moving it through a uniform magnetic field(b) The self induced emf produced by changing current in a coil always tends to decrease the current(c) Inserting an iron core in a coil increases its coefficient of self induction(d) According to Lenz's law, the direction of the induced current is such that it opposes the flux change that causes it

Nuclear fission experiments show that the neutrons split the uranium nuclei into two fragments of about same size. This process is accompanied by the emission of several

What is the unit for EMF?

Kinetic energy of emitted cathode rays is dependent on(a) Only voltage(b) Only work function(c) Both (a) and (b)(d) It does not depend upon any physical quantity

The critical angle of a material is the angle of incidence for which the angle of refraction is:

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.

Approximate height of ozone layer above the ground is(a) 60 to 70 km(b) 59 km to 80 km(c) 70 km to 100 km(d) 100 km to 200 km

A magnetic needle kept parallel to a magnetic field requires a work W to be rotated by 60. The necessary torque required to keep the needle in this position is:

Two parallel circular coils of equal radii having equal number of turns placed coaxially and separated by a distance equal to the radii of the coils carrying equal currents in same direction are known as:

Keeping dissimilar poles of two magnets of equal pole strength and length same side, their time period will be(a) Zero(b) One second(c) Infinity(d) Any value