Give reason for the following
High reverse voltage does not appear across an LED.

Why does sky appear blue?

Give Scientific reasons to the following: Solute enters into the xylem from cortex of roots only by passing through symplastic pathway across the endodermis.

The voltage across 8 ohm resistance is

An amplifier is represented by the circuit shown in Fig. Here r_(i) is the input resistance of the amplifier and the voltage V_(i) is appearing across it. This voltage is amplified by a factor A_(V) and appears across the load as voltage V_(0) An external voltage V_(s) is applied at the input terminals of the amplifier via series resistance R_(S). What will be the apparent gain A_(V)(=V_(0)//V_(s)) of the ampilifier in terms of A_(V), R_(S) and r_(i).

Why does star appears red in colour?

When a voltemeter is put across a part of the circuit, does it read slightly less or more than the original voltage drop across the part? Explain.

Give examples of changes which can be reversed easily.

Answer the following questions: An applied voltage signal consists of a superposition of a dc voltage and an ac voltage of high frequency. The circuit consists of an inductor and a capacitor in series. Show that the dc signal will appear across C and the ac signal across L.

Give a brief account of LED.