Answer: thanks for the point
Explanation:
Answer: D) 3.2 × 10^8
Explanation: Insulators are best described as materials which are poor conductors of electricity and hence do not allow passage of electricity through them. Resistivity are hence used to describe property or characteristic of a material which does not allow the flow or passage of electric current.
In summary, materials which high resistivity values are referred to as Insulators. Conversely, those with low resistivity or high conductivity values are called conductors while those with intermediate values are named semiconductors.
In the question given above, the material with a resistivity value of 3.2 × 10^8 - - - has a very high resistivity value (320000000Ω), the other options given have very low resistivity values ; 0.0000000017, etc and are most likely to be conductors due to their excessively low resistivity values.
Answer:
The answer is C.) 300,000,000 m/s
Explanation:
Light travels at a constant rate of 300,000,000 m/s. this can be determined by dividing the distance (144,000,000,000 meters) by the time (480 seconds). that's pretty fast. in fact, nothing can travel any faster than this. ever.
Answer:
a. 2 Hz b. 0.5 cycles c . 0 V
Explanation:
a. What is period of armature?
Since it takes the armature 30 seconds to complete 60 cycles, and frequency f = number of cycles/ time = 60 cycles/ 30 s = 2 cycles/ s = 2 Hz
b. How many cycles are completed in T/2 sec?
The period, T = 1/f = 1/2 Hz = 0.5 s.
So, it takes 0.5 s to complete 1 cycles. At t = T/2 = 0.5/2 = 0.25 s,
Since it takes 0.5 s to complete 1 cycle, then the number of cycles it completes in 0.25 s is 0.25/0.5 = 0.5 cycles.
c. What is the maximum emf produced when the armature completes 180° rotation?
Since the emf E = E₀sinθ and when θ = 180°, sinθ = sin180° = 0
E = E₀ × 0 = 0
E = 0
So, at 180° rotation, the maximum emf produced is 0 V.
The negative sign on the acceleration is only a vector quantity that means the object is accelerating to the left. Hence, we can only focus on it magnitude which is 4 m/s^2. Acceleration is the change in velocity over time. The change in velocity must be 24 m/s - 0 m/s, if you want the object to stop. Therefore,
a = (v2 - v1)/t
4 = (24 - 0)t
t = 6 seconds
The object will stop after 6 seconds.