Answer:
option D
Explanation:
given,

increase the intensity by factor of 9
I₁ = I₀
I₂ = 9 I₀
now,




A₂ = 3 A₁
hence, amplitude increase with the factor of 3
so, the correct answer is option D
Answer:
Current, I = 0.0011 A
Explanation:
It is given that,
Diameter of rod, d = 2.56 cm
Radius of rod, r = 1.28 cm = 0.0128 m
The resistivity of the pure silicon, 
Length of rod, l = 20 cm = 0.2 m
Voltage, 
The resistivity of the rod is given by :


R = 893692.30 ohms
Current flowing in the rod is calculated using Ohm's law as :
V = I R


I = 0.0011 A
So, the current flowing in the rod is 0.0011 A. Hence, this is the required solution.
It is because that is how mirrors work, they reflect light, and since we see objects because we are seeing the light these objects reflect, what is reflected back by the mirror is what we see.
Answer:
a. If an object's speed is constant, then its acceleration must be zero.
FALSE
As we know that acceleration is defined as the rate of change in velocity

so we can not say anything about the acceleration when speed is given to as and no information is given about velocity
b. If an object's acceleration is zero, then its speed must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity

Since we know that if acceleration is 0 then velocity must be constant and hence speed is also constant
c. If an object's velocity is constant, then its speed must be constant.
TRUE
Since velocity is constant then it shows that its magnitude and direction both are constant so its speed is also constant.
d. If an object's acceleration is zero, its velocity must be constant.
TRUE
As we know that acceleration is defined as the rate of change in velocity

Since we know that if acceleration is 0 then velocity must be constant
e. If an object's speed is constant, then its velocity must be constant.
FALSE
Speed is just the magnitude so we can not say about its direction and hence if speed is constant then velocity may or may not change