Given that metal cases of electrical appliances are connected to the wire, let's select the statement which is not correct from the list of statements.
The earth wire is used to protect you and help reduce the risk of receiving an electric shock. The earth wire reduces the risk of electric shock by creating a path for a fault or lose current to flow to the Earth.
The Live wire may become loose and touch the metal case. In this case, the earth wire will channel the fault current to the earth thereby reducing the risk of electric shock.
If the metal case becomes live, the earth wire conducts current to the ground. This helps prevent electric shock from the metal case.
The Earth wire has low or no resistance. It is always made of copper.
It provides a low resistance path to the ground.
Therefore, the statement ''the earth wire needs to have high resistance'' is NOT current.
ANSWER:
C. The earth wire needs to have a high reistance.
Answer:
The Sun-Earth-Moon system happens to exhibit a striking geometric coincidence, which we examine in the first problem. PROBLEM 1. To an observer on Earth, the Sun and the Moon subtend almost the same angle in the sky. The average angle is 0.52 degrees for the Moon and 0.53 degrees for the Sun.
Answer:
B
Explanation:
F = ma , a = F/m
a1 = F/10 and a2 = F/4
Since Force is constant, a2 will we greater than a1
Answer:
a) r = 6122 m and b) v = 32.5 m / s
Explanation:
a) The train in the curve is subject to centripetal acceleration
a = v2 / r
Where v is The speed and r the radius of the curve
They indicate that the maximum acceleration of the person is 0.060g,
a = 0.060 g
a = 0.060 9.8
a = 0.588 m /s²
Let's calculate the radius
v = 216 km / h (1000m / 1km) (1 h / 3600 s =
v = 60 m / s
r = v² / a
r = 60² /0.588
r = 6122 m
b) Let's calculate the speed, for a radius curve 1.80 km = 1800 m
v = √a r
v = √( 0.588 1800)
v = 32.5 m / s
