Answer:
Hydrogen reacts with oxygen to produce water, which releases energy.
Explanation:
In any fuel cell chemical bonds are formed and energy is released . It is a redox reaction . Bond energy is converted into electrical energy.
In the given option , first option is not possible because methane reacts with oxygen to give carbon dioxide and water .
third and fourth option are ruled out because chemical reactions are using energy . No energy is released . so they are not possible.
Since transformers use laws that require time changing quantities (alternating current), the battery would produce no voltage on the secondary windings. In fact the primary winding would short out the battery to a large extent since the resistance of its copper windings would be very low.
In reality, as the battery was first connected to the primary, a very short blip of voltage would appear on the secondary as the magnetic field initially grew in the core (that would constitute a time-changing magnetic field required for the device to work). But it would immediately go away afterwards and that output cannot be determined without actually doing the experiment due to so many unknowns.
But this question isn't looking for that explanation. It's kind of a trick question.
A ) The displacement:
d = v o t - (gt²) / 2 =
= 19.6 m/s × 1 s - ( 9.8 m/s² x 1 s² ) / 2 =
= 19.6 m - 4.9 m = 14.7 m
b ) v = v o - g t
0 = 19.6 m/s - 9.8 t ( when the ball is at the highest point )
9.8 t = 19.6
t = 19.6 : 9.8
t = 2 s
h = v o t - (gt²)/2 = 19.6 x 2 - ( 9.8 x 4 ) / 2 = 39.2 - 19.6
h = 19.6 m
c ) h = gt² / 2
19.6 = 9.8 t²/2
9.8 t² = 39.2
t² = 39.2 : 9.8
t² = 4
t 2 = 2 s ( and we know that t 1 = 2 s )
t = t 1 + t 2 = 2 s + 2 s = 4 s
CR < CY < CB
<h3>Which factors affect the critical angle for a given pair of media?</h3>
The factors which affect the critical angle are
(a) The colour (or wavelength) of light
(b) The temperature
(i) Effect of colour of light: The critical angle for a pair of media is less for the violet light and more for the red light. Thus the critical angle increases with the increase in wavelength of light.
(ii) Effect of temperature: The critical angle increases with increase in temperature because on increasing temperature of medium, its refractive index decreases.
According to the question,
μ 1 sinCR =1
μ 2 sinCY =1
μ 3 sinCB =1
μ 1 > μ 2 and μ 2 > μ 3
⟹μ 1 > μ 2 > μ 3
CR < CY < CB
Thus,
The critical angle increases with the increase in wavelength of light.
Learn more about wavelength of light here:
brainly.com/question/27557868
#SPJ1
