Wave Optics — Physics STD 12 Science — Question

Assertion  :   If a proton and an electron are placed in the same uniform electric field. They experience different acceleration.
Reason     : Electric force on a test charge is independent of its mass.(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.

In a PNP transistor the base is the N-region. Its width relative to the P-region is (a) Smaller(b) Larger(c) Same (d) Not related

Two circular loops of equal radii are placed coaxially at some separation. The first is cut and a battery is inserted in between to drive a current in it. The current c~anges slightly because of the variation in resistance with temperature. During this period, the two loops:

1. Attract each other.
2. Repel each other.
3. Do not exert any force on each other.
4. Attract or repel each other depending on the sense of the current.

At absolute zero, Si acts as:

If a small amount of antimony is added to germanium crystal:

Assertion :   An ac generator is based on the phenomenon of self-induction.
Reason     : In single coil, we consider self-induction only.(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.

 How many types of electron emissions exist?

A coil of insulating wire is connected to battery. If it is moved towards a galvanometer then its point gets deflected because.

Assertion :   A paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled.
Reason     : The magnetisation does not depend on temperature.(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.

If the distance between H and Cl in HCl molecule is 1.28 A, then the value of electric dipole moment of this molecule will be (in Coulomb-meter):