Heat from burning fuel warms the walls of the firebox section of the furnace in
A. a hot-water heating system.
B. a hot-air heating system.
C. a compressor compartment.
D. an evaporation system.
Answer:
0.54 A
Explanation:
Parameters given:
Number of turns, N = 15
Area of coil, A = 40 cm² = 0.004 m²
Change in magnetic field, ΔB = 5.1 - 1.5 = 3.6 T
Time interval, Δt = 2 secs
Resistance of the coil, R = 0.2 ohms
To get the magnitude of the current, we have to first find the magnitude of the EMF induced in the coil:
|V| = |(-N * ΔB * A) /Δt)
|V| = | (-15 * 3.6 * 0.004) / 2 |
|V| = 0.108 V
According to Ohm's law:
|V| = |I| * R
|I| = |V| / R
|I| = 0.108 / 0.2
|I| = 0.54 A
The magnitude of the current in the coil of wire is 0.54 A
Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
Total distance covered = 384 Km
Total time taken to travel from A to B = 8 hours [from 8 am to 4 pm, there are 8 hours]
We know, Average speed = Total Distance Travelled/ Total Time Taken
Therefore, average speed = 384 Km/8 h = 384000m/8×60×60s =(384000/28800)m/s
= 13.3 m/s
Answer is 13.3 m/s
As per the question, the distance travelled by bobsled [s] = 100 m
The time taken by the bobsled to travel that distance [t] = 25 s
We are asked to calculate the speed of the bobsled.
The speed of the bobsled is calculated as -
Hence, the correct answer to the question is A. 4 m/s.
