Answer:
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Explanation:
True or false
B. a thick wire
C. a solar cell
D. a generator
Answer: The correct answer is a thick wire.
Explanation:
In the given options of the problem, a car battery is needed to generate an electrical current. It forces the electrons to flow. It makes the current flow in the circuit.
Solar cell is a device which converts the solar energy into the electrical energy. It can increase the voltage and generate an electrical current.
Generator is a device which converts the mechanical energy into the electrical energy. It can increase the voltage and generate an electrical current.
A thick wire is not used to increase voltage and generate an electrical current. The thick wire has low resistance in comparison to the thin wire.
Therefore, the correct option is (B).
d)The unit for work is a joule. The unit for power is a watt, which is a joule per second.
Answer:
Option (d) is correct.
Explanation:
Work done is given by :
W = Fd, where F is force and d is displacement
Unit of work done :
The SI unit of force is Newton (N) and that of displacement is meter (m). So, the unit of work done is N-m. It is call Joule. It means that the unit of work done is Joule.
Power is given by rate at which the work is done. It is given by :
P = W/t, W is work done and t is time
Unit of power:
Unit of work is Joule (J) and that of time is second (s). It means that the unit of power is Watt and it is equal to Joule/second
Hence, the correct option is (d) "The unit for work is a joule. The unit for power is a watt, which is a joule per second".
Answer: The unit for work is a joule. The unit for power is a watt, which is a joule per second.
Explanation:
Answer:
The height of the airplane is 3312.4 meters.
Explanation:
Given that,
Speed of the airplane, v = 1100 km/h = 300 m/s
It takes 26 s for the engine to hit the ground. We need to find the height of the airplane. Using second equation of motion to find it as :
Here, u = 0 and a = g
The height of the airplane is 3312.4 meters.
(b) What will the voltmeter read if the dielectric is now pulled partway out so it fills only one-third of the space between the plates?
(A) 3.9
When a dielectric is inserted between the plates of a capacitor, the capacitance of the capacitor increases according to the equation:
(1)
where
C' is the final capacitance
k is the dielectric constant
C is the original capacitance
The capacitance is inversely proportional to the to voltage across the plates:
(2a)
where Q is the charge stored and V the potential difference across the plates. We can rewrite C' (the capacitance of the capacitor filled with dielectric) as
(2b)
Substituting (2a) and (2b) into (1), we find
(3)
where
V = 45.0 V is the original voltage across the capacitor
V' = 11.5 V is the voltage across the capacitor filled with dielectric
Solving for k,
(B) 22.8 V
When the dielectric is partially pulled away, the system can be assimilated to a system of 2 capacitors in parallel, of which one of them is filled with dielectric and the other one is not.
Keeping in mind that the capacitance of a parallel-plate capacitor is proportional to the area of the plates:
and in this case, the area of the capacitor filled with dielectric is just 1/3 of the total, we can write:
where C1 is the capacitance of the part non-filled with dielectric, and C2 is the capacitance of the part filled with dielectric. The total capacitance of the system in parallel is
Substituting,
This is equivalent to a capacitor completely filled with a dielectric with dielectric constant k=1.97. Therefore, using again eq.(3), we find the new voltage: