Electrical engineering - practice for 14 year olds - page 5 of 7
Number of problems found: 121
- Electric 25011
How much voltage do we measure on a 400Ω resistor when an electric current of 55 mA passes through it? - Copper Cu wire
Copper wire with a diameter of 1 mm and a weight of 350 g is wound on a spool. Calculate its length if the copper density is p = 8.9 g/cm cubic. - Closed circuit
There is a voltage source with U1 = 12 V in a closed circuit and with internal resistance, R1 = 0.2 Ω. The external resistance is R2 = 19.8 Ω. Find the electric current and terminal voltage. - Temperature 22861
The small bulb's socket has a reading of 6.3V/0.3A, which applies to its filament when the bulb is on. Determine the electrical resistance of the fiber under the given condition (the temperature of the fiber corresponds to about 2800°C)
- Short-circuit 22841
An external circuit with a resistance of 3.8 Ω is connected to an electrical voltage source with Ue=12 V. A current of 3 A passes through the circuit. Specify: source terminal voltage, the internal resistance of the source, maximum short-circuit current. - Energy consumption
The device is connected to 230V and draws a 3.5A current. Power consumption is 1932kJ. How many minutes has this device been in operation? - Cooker
A current of 2A passes through the immersion cooker at a voltage of 230V. What work do the electric field forces do in 2 minutes? - The copper wire
The copper wire bundle with a diameter of 2.8mm weighs 5kg. How many meters of wire are bundled if 1m³ of copper weighs 8930kg? - Transformer 20073
The transformer is oil-cooled and transforms a power of 20MW with an efficiency of 92%. Determine the temperature of the oil at the outlet of the transformer if the oil was 20°C when it entered the transformer. 2.5 liters of oil will flow through the tran
- Electrical 19373
At a certain point, we measured a voltage of 3.74V at a current of 170mA at the terminals of a resistor connected to an electrical circuit. Calculate the resistance of the resistor. - Calculation 16653
The LED parameters are: ULed is 3V, Current 100mA Take measures so that the LED at the U 12V supply is not destroyed. Perform the calculation and also the wiring diagram. - Connected 12261
At a voltage of 16 V between the ends of the resistor, a current of 200 mA flows through the resistor. What current will flow through the resistor when connected to 48 V? - Measurement 12251
The measurement showed that a current of 160 mA flows through the appliance at a voltage of 4 V. What current flows through this appliance when connected to a voltage of 12 V? - Voltmeter range
We have a voltmeter which, in the original set, measures voltage to 10V. Calculate the size of the ballast resistor for this voltmeter if we want to measure the voltage up to 50V. Voltmeter's internal resistance is 2 kiloohm/Volt.
- Driver's 7771
How long does it take for a 15C charge to pass through the driver's average if a 3mA current passes through the driver? - Transformer
Solve the textbook problems - transformer: a) N1 = 40, N2 = 80, U2 = 80 V, U1 =? b) N1 = 400, U1 = 200 V, U2 = 50 V, N2 =? - Electric input power
Solve problems related to electric power: a) U = 120 V, I = 0.5 A, P =? b) P = 200 W, U = 230 V, I =? c) I = 5 A, P = 2200W, U =? - Refrigerator 6703
Calculate how much we will pay for 1 hour of consumed electrical energy if the seller sets a price of 0.126 euros for 1 kWh (all appliances together for 1 hour of work). Table: Appliance Power (W) Washing machine 2300 W Bulb 40W Refrigerator 200W TV 110W - Bulbs and electricity
In the sports hall, 875 identical light bulbs light for 2 hours. How long do 100 such light bulbs consume the same amount of electricity?
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