Atoms — Physics STD 12 Science — Question

Check the wrong statement:

In a communication system, noise is most likely to affect the signal (a) At the transmitter(b) In the channel or in the transmission line (c) In the information source(d) At the receiver

A copper ring is kept horizontal and a bar of magnet is dropped in the direction of the axis of the ring. The acceleration of the falling magnet will be:

Which of the following about potential at a point due to a given point charge is true?
The potential at a point P due to a given point charge.

When the speed of a dc motor increases the armature current(a) Increases(b) Decreases(c) Does not change(d) Increases and decreases continuously

Two lithium nuclei in a lithium vapour at room temperature do not combine to form a carbon nucleus because:

1. A lithium nucleus is more tightly bound than a carbon nucleus.
2. Carbon nucleus is an unstable particle.
3. It is not energetically favourable.
4. Coulomb repulsion does not allow the nuclei to come very close.

A P-type semiconductor can be obtained by adding (a) Arsenic to pure silicon(b) Gallium to pure silicon(c) Antimony to pure germanium(d) Phosphorous to pure germanium