Electrical engineering - practice for 13 year olds
Number of problems found: 111
- Heat energy
Energy is measured using the unit Joule (J). Temperature is measured using the unit degree Celsius °C). To increase the temperature of 1 liter of water by 1°C, 4200 J of heat energy is required. (a) Kelly wants to increase the temperature of 2 liters of w - Transformer 3
A 200/115 V transformer has an LV (Low voltage) side resistance of 0.06 Ohm. What is the resistance referred to HV side (high voltage)? - Accumulator 82755
The battery capacity is 50 Ah. With a current of 5A, we charge the accumulator to 100% capacity in 10 hours. To what percentage of capacity can we charge the accumulator with a current of 2A in 15 hours? - Resistance 82714
A load of 23.5 ohm is connected to an ideal voltage source of 30V, and a current of 1.2A passes through the circuit. Determine the magnitude of the source's internal resistance and the short-circuit current.
- Corresponds 82534
A current of 0.1 A can lethally affect a human body with a resistance of 3 kΩ. What voltage corresponds to this current? - Resistance 82533
A current of 275 mA passes through the filament of a light bulb with a resistance of 800 Ω. What voltage is the bulb connected to? - Appliance 82079
The voltage at the terminals of the appliance is 4.5 V. A current of 0.5A passes through the appliance. What voltage must the appliance have if a current of 0.7A is to pass through it? - ELECTRICAL 81742
A cooker connected to a 40 V voltage source draws a current of 0.5 A. DOES THE SIZE OF THE ELECTRICAL WORK DETERMINE WHICH COOKER DOES IN 3 MINUTES? - Resistance 81503
What is the value of the resistance of the rectifier diode in the forward direction if the current IF = 5 A flows through it and the voltage between the anode UF = 820 mV?
- Resistor 81502
How big a series resistor do we need to connect to the LED if a voltage drop of 3.2 V is to be created on it and a current of 16 mA flows through the diode? We want to connect the diode to a voltage of 5V. - Horsepower 81496
The electric motor has an efficiency of 80% (power and input ratio). What is the power input of this motor if its power is 5 horsepower (HP)? Enter the result in kilowatts (kW) and round to one decimal place (1 HP = 3/4 kW). - Several resistors
We have a box with the same resistors, so all of them have a resistance value of 200 ohms. Draw the connection of several resistors so that the resulting resistance is: a) 100 b) 120 (only 4 resistors) - Effectiveness 80711
When testing the effectiveness of an electric cooker with data of 220 V, 1200 W, 1 kg of water at a temperature of 15 degrees Celsius was boiled for 8.5 minutes. Calculate the stove efficiency corresponding to these data - Resistances 80706
The current I = 4A branches into three wires with resistances R1 = 2Ώ, R2 = 5Ώ, R3 = 10Ώ. Calculate the total resistance of the connection and the voltage of the source. How big are the currents in each wire?
- Determine 80705
The bulb is rated 6 V, 0.2 A. Determine the current rating of the bulb. - Automatically 80704
The electric circuit breaker automatically switches off the circuit of the 220 V electrical network at a current of 6 A. Determine the maximum power in the protected circuit. - Resistance 80703
An immersion cooker has a resistance of 30 ohms and is connected to a voltage of 120 V. How much heat is generated in 2 hours? - Consumption 80702
A current of 500 mA passed through the filament of a light bulb with a resistance of 400 ohms. What is the consumption of a light bulb in 5 hours? - Resistance 80699
The immersion cooker plate has data 220 V, 300 W. What is the resistance of the heating wire?
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