Answer:
10500 J/kg/*C
Explanation:
Quantity of heat required=mass of substance x specific heat capacity x change in temperature
Quantity of heat required=0.25 x 4200 x [30-20]
Quantity of heat required=0.25 x 4200 x 10
Quantity of heat required=10500 J/kg/*C
Answer:
ultraviolet light shining on the minerals will cause them to give off visible light.
Explanation:
Here we know that in all electromagnetic waves have certain range of energy
Here in the above case when a given frequency range of electromagnetic wave incident on the fluorescent mineral then that mineral will absorb few amount of energy and the remaining energy will throw back into the surrounding again.
So here the main concept is that when a electromagnetic wave which is higher in energy then visible light incident on fluorescent material then it will absorb some amount of energy and the remaining energy is released in form of light
So here energy more than visible light is for ultraviolet light only
so here the correct answer would be
ultraviolet light shining on the minerals will cause them to give off visible light.
Answer:
Explanation:
Given that,
Number of turns of coil
N = 50 turns
Initial area of plane
A1 = 0.18 m²
The coil it stretch to a no area in time t = 0.1s
No area implies that the final area is 0, A2 = 0 m²
Constant magnetic field strength
B = 1.51 T
EMF?
EMF is given as
Using far away Lenz law
ε = —N• dΦ/dt
Where Φ = BA
Then,
ε = —N• d(BA)/dt
Since B is constant,
ε = —N•B dA/dt
ε = —N•B (∆A/∆t)
ε = —N•B(A2—A1)/(t2-t1)
ε = —50 × 1.51 (0—0.18)/(0.1—0)
ε =—75.5 × —0.18 / 0.1
ε = 135.9 V
The induced EMF is 135.9V
Fleming’s left hand rule stated that if the index finger points toward magnetic flux, the thumb towards the motion of the conductor, then the middle finger points towards the induced emf.
Since the area lines in the plane, then the induced emf will be out of the page
Answer:
Color
Explanation:
Thus, for stars, considering them as “black bodies”, we can get an approximate figure for their temperature by measuring their dominant frequency (color). Technically scientists measure the brightness of the blue light and that of red light from the star, and from this they can calculate the temperature of the star.
I’m not sure but when’s the deadline
