Answer:
Given:
Thermal Kinetic Energy of an electron, 
= Boltzmann's constant
Temperature, T = 1800 K
Solution:
Now, to calculate the de-Broglie wavelength of the electron,
:

(1)
where
h = Planck's constant = 
= momentum of an electron
= velocity of an electron
= mass of electon
Now,
Kinetic energy of an electron = thermal kinetic energy



(2)
Using eqn (2) in (1):

Now, to calculate the de-Broglie wavelength of proton,
:

(3)
where
= mass of proton
= velocity of an proton
Now,
Kinetic energy of a proton = thermal kinetic energy



(4)
Using eqn (4) in (3):

Answer:
<em>B. 68.6m</em>
Explanation:
<u>Free Fall Motion
</u>
When a body is left to move in the air with no friction, the motion is ruled only by the force of gravity. The vertical distance a body travels in the air after a time t is
.

We know the egg takes 3.74 seconds to reach the ground. The height it was launched from is


The closest correct option is
B. 68.6m
Answer:
The current is halved
Explanation:
The relationship between the current and the resistance is given by Ohm's Law, as follows:

where,
V = Voltage
I = Current
R = Resistance
Therefore, if we double the resistance:

Hence the correct option is:
<u>The current is halved</u>
Answer:
The influence of diameter of the blood vessel on peripheral resistance is significant because resistance is inversely proportional to the fourth power of the diameter.
Explanation:
The influence of diameter of the blood vessel on peripheral resistance is significant because the relation between the peripheral resistance and the diameter is given as, resistance is inversely proportional to the fourth power of the diameter. Thus, with small increase or decrease in the value of diameter, the peripheral resistance may vary by a significant amount.