Given a power system with the following data Transmission Line Data (values in p. u.) From Bus To Bus R X Tot. Charging
1 2 0.000 0.500 0.000
1 3 0.000 0.333 0.000
1 4 0.000 0.500 0.000
2 3 0.000 0.250 0.000
4 3 0.000 0.400 0.000
a) Write down the Ybus matrix
b) How would Ybus change with a capacitor Q

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk