Answer:
The new resistance becomes half of the initial resistance.
Explanation:
The resistance of a wire is given by :

= resistivity of material
L and A are linear dimension
If the electrical wire is replaced with one having every linear dimension doubled i.e. l' = 2l and r' = 2r
New resistance of wire is given by :




The new resistance becomes half of the initial resistance. Hence, this is the required solution.
Answer:
A). σ = 3.823 x
/N-
B).
C/
C).
J
Explanation:
A). We know magnitude of charge per unit area for a conducting plate is given by

where, E is resultant electric field = 1.2 x
V/m
is permittivity of free space = 8.85 x
/N-
k is dielectric constant = 3.6
∴
= 3.6 x 8.85 x
x 1.2 x 
= 3.823 x
/N-
B).Now we know that the magnitude of charge per unit area on the surface of the dielectric plate is given by


C/
C).
Area of the plate, A = 2.5 
= 2.5 x 

diameter of the plate, d = 1.8 mm
= 1800 m
∴ Total energy stored in the capacitor


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Answer:
minimum power should be used to operate the air conditioner is 4000 W
Explanation:
given data
students n = 160
power p = 125 W
COP = 5.0
to find out
what minimum power should be used
solution
we know the COP formula that is given below
COP = students × power / minimum power
minimum power = n × p / COP
put all value
minimum power = n × p / COP
minimum power = 160 × 125 / 5
minimum power = 4000 W
minimum power should be used to operate the air conditioner is 4000 W
Answer:4.05 s
Explanation:
Given
First stone is drop from cliff and second stone is thrown with a speed of 52.92 m/s after 2.7 s
Both hit the ground at the same time
Let h be the height of cliff and it reaches after time t

For second stone
---2
Equating 1 &2 we get




