Answer:
Friction force is the force that one object exerts in another when the two rub against each other. Most of the time, friction force opposes the motion of an object.
Explanation:
8. In soft magnetic materials such as iron, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized state.
9. According to Lenz’s law, if the applied magnetic field changes,
a. the induced field attempts to keep the total field strength constant.
b. the induced field attempts to increase the total field strength.
c. the induced field attempts to decrease the total field strength.
d. the induced field attempts to oscillate about an equilibrium value.
10. The direction of the force on a current-carrying wire in an external magnetic field is
a. perpendicular to the current only.
b. perpendicular to the magnetic field only.
c. perpendicular to the current and to the magnetic field.
d. parallel to the current and to the magnetic field
Answer:
- Which of the following does not move as a transverse wave?
<em>B. sound waves</em>
because sound waves are longitudinal waves having compressions and rare factions.
Which of these effects describes the change in pitch we hear
moving motorbike goes past?
<em>D</em><em>.</em><em> </em><em>Doppler</em><em> </em><em>eff</em><em>ect</em>
Doppler effect is the phenomenon where there is apparent change in frequency (pitch) and wavelength of a wave due to relative motion of the sound source.
Which of the following does not make use of total internal reflection.
<em>B</em><em>.</em><em> </em><em>Endos</em><em>cop</em><em>e</em>
Endoscope doesn't use total internal reflection since no refraction takes place.
On the Newtonian theory of gravity, gravitation affects anything with mass. Assuming that none of the answer choices is the only thing that exists in the universe, all of the answer choices are subject to the law of universal gravitation (hence “universal”).
Satellites, water, frogs, and stars all have mass as they are all composed of matter. Thus, all four answer choices should be circled.
Answer:
13.51 nm
Explanation:
To solve this problem, we are going to use angle approximation that sin θ ≈ tan θ ≈ θ where our θ is in radians
y/L=tan θ ≈ θ
and ∆θ ≈∆y/L
Where ∆y= wavelength distance= 2.92 mm =0.00292m
L=screen distance= 2.40 m
=0.00292m/2.40m
=0.001217 rad
The grating spacing is d = (90000 lines/m)^−1
=1.11 × 10−5 m.
the small-angle
approx. Using difraction formula with m = 1 gives:
mλ = d sin θ ≈ dθ →
∆λ ≈ d∆θ = =1.11 × 10^-5 m×0.001217 rad
=0.000000001351m
= 13.51 nm
