Galileo only saw the system through a scope
Answer: False but read why
Heated water molecules expands ( become less dense) but they do float to the top.
Answer:
Explanation:
Given that,
Radius r = 15cm = 0.15m
Area of the circular loop can be determined using the formula for area of a circle
A = π r²
A = π × 0.15²
A = 0.0708 m²
Magnetic field B = 1.2T in positive z direction
B = 1.2 •k T.
If loop is remove from the field in the time interval
∆t = 2.3ms = 2.3×10^-3s
We want to find the average EMF and it is given as
ε = —∆Φ/∆t
The final flux is zero
Φf = 0
Where magnetic flux is given as
Φi = BA Cosθ
Where θ=0 since the area and the magnetic field point in the same direction.
Φi = BA Cos0
Φi = BA
Φi = 1.2 × 0.0708
Φi = 0.0848 Vs
Then, ε = —∆Φ/∆t
ε = —(Φf — Φi) / ∆t
ε = —(0-0.0848) / (2.3×10^-3)
ε = 0.0848 / (2.3×10^-3)
ε = 36.88 V
The EMF is 36.88 Volts
Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.
Answer: 1.176×10^-3 s
Explanation: The time constant formulae for an RC circuit is given below as
t =RC
Where t = time constant , R = magnitude of resistance = 21 ohms , C = capacitance of capacitor = 56 uf = 56×10^-6 F
t = 56×10^-6 × 21
t = 1176×10^-6
t = 1.176×10^-3 s
