Answer:
0.03 A
Explanation:
From the question given above, the following data were obtained:
Voltage (V) = 12 V
Resistor (R) = 470 Ω
Current (I) =?
From ohm's law, the voltage, current and resistor are related by the following formula:
Voltage = current × resistor
V = IR
With the above formula, we can obtain the current in the circuit as follow:
Voltage (V) = 12 V
Resistor (R) = 470 Ω
Current (I) =?
V = IR
12 = I × 470
Divide both side by 470
I = 12 / 470
I = 0.03 A
Thus, the current in the circuit is 0.03 A
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:
f=171.43Hz
Explanation:
Wave frequency is the number of waves that pass a fixed point in a given amount of time.
The frequency formula is: f=v÷λ, where <em>v</em> is the velocity and <em>λ</em> is the wavelength.
Then replacing with the data of the problem,
f=
f=171.43
f=171.43 Hz (because 
, 1 hertz equals 1 wave passing a fixed point in 1 second).
Answer:
the answer is 5 electrons
Explanation:
because its the same name as the amount of protons
Answer:
54 Kobo
Explanation:
Units of <u>electricity</u> are measured in kilowatt hours (kWh).
Given information:
- 900 watt electric iron
- Appliance usage = 4 hours a week for 5 weeks
- Unit cost of electricity = 3 Kobo per kWh
<h3><u>Step 1</u></h3>
Convert the wattage of the electric iron from watts to kilowatts.
1000 watts (W) = 1 kilowatt (kW)
⇒ 900 watts = 1 ÷ 1000 = 0.9 kilowatts
This means that the power consumption of the electric iron is 0.9 kW per hour of use.
<h3><u>Step 2</u></h3>
Total hours spent pressing clothes:
= 4 hours per week for 5 weeks
= 4 × 5
= 20 hours
<u>Total power consumption</u>:
= number of kW × number of hours
= 0.9 × 20
= 18 kWh
<h3><u>Step 3</u></h3>
To find the <u>total cost</u>, multiply the total kWh by the cost per kWh:
⇒ Cost = 18 × 3 = 54 Kobo
