Heat dissipation
Production of eddy currents
Excessive current discharge
Excessive voltage discharge
Correct answer is A
The primary reason that power is transmitted at high voltages is to increase efficiency. As electricity is transmitted over long distances, there are inherent energy losses along the way. High voltage transmission minimizes the amount of power lost as electricity flows from one location to the next. How? The higher the voltage, the lower the current. The lower the current, the lower the resistance losses in the conductors. And when resistance losses are low, energy losses are low also. Electrical engineers consider factors such as the power being transmitted and the distance required for transmission when determining the optimal transmission voltage
Pair of calipers
Meter rule
Micrometer screw gauge
Tape rule
Correct answer is A
No explanation has been provided for this answer.
25.2N
17.4N
12.6N
9.0N
Correct answer is B
Weight of water displaced = upthrust = 30 - 21 = 9N
Mass of water displaced = \(\frac{9}{10}\) = 0.9kg
Volume of object = 9 × 10\(^{-4}\)m\(^3\)
= (9 × 10\(^{-4}\)) (1.4 ×103)
= 1.26kg = 12N
30 - 12.6 = 17.4N
The efficiency of energy conversion on the energy flow through a hydroelectric power is?
\(\frac{E1}{E2}\)
\(\frac{E3}{E2}\)
\(\frac{E2}{E1}\)+ E2
\(\frac{E2}{E3}\) + E1
Correct answer is B
Efficiency = \(\frac{\text{useful energy output from machine}}{\text{energy input into machine}}\)
= \(\frac{E3}{E2}\)
20.0kgms\(^{-1}\)
10.0kgms\(^{-1}\)
5.0kgms\(^{-1}\)
2.5kgms\(^{-1}\)
Correct answer is B
Impulse = Change in momentum
m (v - u)
5 (2.0)
= 5 x 2 = 10.0kgm\(^{-1}\)
= 10.0kgms\(^{-1}\)