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.
Answer:
Explanation:
Y = 5 Sin27( .2x-3t)
= 5 Sin(5.4x - 81 t )
Amplitude = 5 m
Angular frequency ω = 81
frequency = ω / 2π
= 81 / (2 x 3.14 )
=12.89
Wave length λ = 2π / k ,
k = 5.4
λ = 2π / 5.4
= 1.163 m
Phase velocity =ω / k
= 81 / 5.4
15 m / s.
The wave is travelling in + ve x - direction.
Answer:
Explanation:
The net force exerted on the mass is the sum of tension force and the external force of gravity.
is the tension force.
is the force of gravity.
where 
is the rope's radius from the fixed point.
From the net force equation above:
Hence the tension force is 6.046N
Answer:
The rock's speed after 5 seconds is 98 m/s.
Explanation:
A rock is dropped off a cliff.
It had an initial velocity of 0 m/s. And now it is moving downwards under the influence of gravitational force with the gravitational acceleration of 9.8 m/s².
Speed after 5 seconds = V
We know that acceleration = average speed/time
In our case,
g = ((0+V)/2)/5
9.8*5 = V/2
=> V = 2*9.8*5
V = 98 m/s
