26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
Answer:
Explanation:
Area of square loop = L²
Flux Φ = area x magnetic field
= L²B
Frequency = f
angular velocity ω = 2πf
a )
Let at time t = 0 , the magnetic field is making 90 degree with the face of the loop
flux through loop = L²B
After time t , coil will turn by angle ω t = 2πft
Flux through the loop = L²B cosω t
Φ (t) = L²B cosω t
= L²B cos2πft
b )
emf induced e
= - d/dt [Φ (t)]
= - d/dt [ L²B cosω t]
= L²B ω sinω t
= L²B 2πf sin2πft
c )
current = e / R
(L²B ω/ R ) sinω t
Power delivered
P(t) = VI ,
VOLT X CURRENT
= AB ω sinω t X ( AB ω/ R ) sinω t
= L⁴B² 4π²f²/R sin²2πft
e )
torque = MB sinω t
τ(t) = i(L²B ) sinω t
= (L²B ω/ R ) sinω t x (L²B ) sinω t
= (L²B )²ω/ R sin²ω t
= (L²B )² 2πf/ R sin²2πft
Answer:
Yes, the answer on <em>how far off the ground a typical truck is happens to be</em> physically realistic.
Explanation:
This concept could be explained with when someone is viewing a picture from a particular distance. The farther the person is from the picture, the smaller the details of the picture and the higher they picture would be unappriciated and vice versa.
Likewise the small truck on ground. <em>The distance off ground the truck is being viewed, the smaller the truck would become.</em>
Answer:
The width of the slit is 0.4 mm (0.00040 m).
Explanation:
From the Young's interference expression, we have;
(λ ÷ d) = (Δy ÷ D)
where λ is the wavelength of the light, D is the distance of the slit to the screen, d is the width of slit and Δy is the fringe separation.
Thus,
d = (Dλ) ÷ Δy
D = 3.30 m, Δy = 4.7 mm (0.0047 m) and λ = 563 nm (563 ×
m)
d = (3.30 × 563 ×
) ÷ (0.0047)
= 1.8579 ×
÷ 0.0047
= 0.0003951 m
d = 0.00040 m
The width of the slit is 0.4 mm (0.00040 m).