Which of the following device is not used for measuring?
a. Forging
b. Steel rule
c. Digital caliper
d. Fixed gages
e. Micrometer
a
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A(n) ____________________ shows how many times a number is taken as a factor.
Fill in the blank(s) with the appropriate word(s).
If a crane has three-part reeving, the hoist line is terminated at the _____.
a. load block b. jib c. boom d. hoist sheave
Emergent plants are sometimes referred to as ____________________ because they grow at the edges of the water garden
Fill in the blank(s) with correct word
A dc, separately excited motor has the following data:
Rated field voltage = 300 V Field constant (K?) = 3 Vs Armature resistance = 2 ? Field resistance = 150 ? The motor is used to drive an assembly line consisting of a conveyor belt moving horizontally. The load on the belt varies depending on the amount of goods being moved. The load torque seen by the motor varies from a maximum of 24 Nm to a minimum of 3 Nm. At all loading conditions, the speed of the motor must be maintained constant and equal to 200 rpm. a. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input to the converter is 240 V (rms). Calculate the range of the triggering angle (minimum and maximum) required to maintain the motor speed at the specified value at all loading conditions. Assume that the armature current is always continuous. b. Another method to achieve the desired operation is to adjust the field voltage. In this case, the armature voltage can be kept constant at some value. Calculate the range of the field voltage (minimum and maximum). Hints: Assume that the maximum value of the field voltage is equal to its rated value (i.e., 300 V). Also assume that the field constant (K?) is linearly proportional to the field voltage.