Answer: If you move a magnet quickly through a coil of copper wire, the electrons will move - this produces electricity.
Explanation:
Answer:
Why are they used:
A carbon brush is a sliding contact used to transmit electrical current from a static to a rotating part in a motor or generator, and, as regards DC machines, ensuring a spark-free commutation.
Answer:
98.1 Joule
Explanation:
Solution,
⇒Mass(m)=10kg
⇒Weight(F)=Mg=10×9.81=98.1N
⇒Distance(d)=1m
Now,
Work done=F×d
=98.1×1
=98.1J
Answer:

Given:
Mass (m) = 6.8 kg
Speed (v) = 5.0 m/s
To Find:
Kinetic energy (KE)
Explanation:
Formula:

Substituting values of m & v in the equation:




Answer:
a)54L/min
b)0.845
Explanation:
a) A x V=
where suffix 1,2,3 refers to the three pipes.
=27L/min+16L/min+11 L/min
=54L/min
b) A x V=54L/min =>
x v
d= 2 cm
x v = 54
v=
x
->
x
=27L/min =>
x 
= 1.3cm
x
= 27
=
x 
Next is to find the ratio of speed i.e 
x
/
x
=>

= 0.845