A rectangular coil 30cm long and 20cm wide has 250 turns. It rotates at the uniform rate of 3000 rev/minute about an axis parallel to its long side and at right angles to a uniform magnetic field of flux density 5×10-2T find the frequency of revolution A60Hz B3000Hz C100Hz D50Hz?
To find the frequency of revolution, we need to convert from revolutions per minute to hertz.
1 revolution = 1/60 minutes
So, the frequency in hertz can be calculated as follows:
Frequency = (3000 revolutions/minute) * (1/60 minutes/second) = 50 Hz
Therefore, the correct answer is option D: 50Hz.
To find the frequency of revolution, we can first convert the given rotation rate into revolutions per second.
Given:
Frequency = 3000 rev/minute
To convert to rev/second, divide by 60:
Frequency = 3000 rev/60s = 50 rev/s
Now, to find the frequency of revolution, we need to consider that one revolution corresponds to the time it takes for the coil to rotate once around its axis.
The time for one revolution can be calculated using the formula:
Time = 1 / Frequency
Given:
Frequency = 50 rev/s
Time = 1 / Frequency = 1 / 50 = 0.02 s
Therefore, the frequency of revolution is 1 / 0.02 s = 50 Hz.
So, the correct option is D. 50 Hz.