Answer: First option
Explanation: The higher the frequency, the higher the energy.
λν=c where λ is the wavelength, ν is the frequency and c is the speed of light. So when wavelength decreases, v increases and so does energy.
An AM radio wave has a very long wavelength. It therefore has a very low frequency and low energy.
A light wave has a very short wavelength. It therefore has a high frequency and high energy.
Answer:
1.7×10^5 ms-1
Explanation:
From
qE= qvB
q= charge on the electron
E = electric field
v= velocity
B= magnetic field
E= vB
v= E/B= 110×10^3/0.6
v= 1.7×10^5 ms-1
Given:
density of air at inlet, 
density of air at inlet, 
Solution:
Now,
(1)
where
A = Area of cross section
= velocity of air at inlet
= velocity of air at outlet
Now, using eqn (1), we get:
= 1.14
% increase in velocity = 
=114%
which is 14% more
Therefore % increase in velocity is 14%
Answer:
True.
Explanation:
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
