ELEX Pre-Board Exam 9

What is the maximum number of electrons in a subshell?

• 2
• 6
• 10
• 14

The repeatability of a servo-controlled robot is within _____ mm rather than a fraction of a mm.

• 2
• 4
• 3
• 5

What is the principal quantum number of a Q shell?

• 6
• 5
• 4
• 7

What time when the voltage across L will be equal to the voltage across R in a series RL transient circuit where E = 24 V, R = 10 Ω and L = 1 H?

• 69.3 ms
• 69.3 s
• 6.93 ms
• 6.93 s

What is the hysteresis loss at a frequency of 60 cycles per second of an audio transformer magnetic core which has a maximum flux density of 10,000 gausses? The volume of solid iron of this core is 66.8 cubic cm and the hysteresis coefficient (a constant that depends upon grade and quality of iron) id 5.35 x 10-4.

• 0.5386 W
• 53.86 W
• 5.386 W
• 5386 W

When two coils of equal inductances are connected in series with coefficient of coupling and their fields in phase, find the total inductance of two coils.

• 2LA
• 2LA (1+k)
• 2kLA
• LA (2 + k)

A 2 μF capacitor with initial charge q0 = 100 μC, is connected across a 100 Ω resistor at t = 0. Calculate the time in which the transient voltage across the resistor drops from 40 to 10 V.

• 2.77 s
• 0.277 ms
• 2.77 ms
• 0.277 s

What do you call a small D.C generator built into alternators to provide excitation current to field windings?

• prime mover
• excitor
• commutator
• load

What is the condition of the diode in a parallel-limiter when the output is developed?

• Shunted
• Conducting
• Cut-off
• Shorted

What is the payload of the industrial robot AEA IRb-60?

• 60 kg
• 80 kg
• 50 kg
• kg