اختبار الشهر الأول ماده الفيزياء للصف الثالث الثانوى

When the external resistance of a battery increases, the voltage difference between its terminals also increases. This is because the increase in resistance causes a decrease in current flowing through the circuit according to Ohm's Law (V = IR). As a result, the voltage drop across the internal resistance of the battery becomes a larger proportion of the total voltage, leading to an increase in the voltage difference between the battery terminals. Therefore, the statement is true.

If the resistances of the two lamps connected in series are R1 and R2, and if R1 is greater than R2, then the current flowing through the circuit will be the same for both lamps. However, since the resistance of lamp 1 is greater, it will experience a larger voltage drop across it compared to lamp 2. Therefore, lamp 1 will have a higher brightness or illumination compared to lamp 2. Hence, the correct answer is "اضاءه مصباح 1 اكبر" which means "Brightness of lamp 1 is greater".

The statement "توصل اجهزه المنزل على التوالى" translates to "Home appliances are connected in series". However, this statement is incorrect. Home appliances are typically connected in parallel, where each appliance has its own separate connection to the power source. Connecting appliances in series would mean that the current flows through one appliance before reaching the next, which is not how home appliances are typically wired.

If the resistance of lamp 1 (R1) is greater than the resistance of lamp 2 (R2), then the current passing through lamp 1 will be smaller than the current passing through lamp 2. Since the brightness of a lamp is directly proportional to the current passing through it, lamp 2 will have a greater brightness compared to lamp 1. Therefore, the answer is "اضاءه مصباح 2 اكبر" (The brightness of lamp 2 is greater).

When the external resistance of the circuit increases to infinity, the voltage at point B (VB) will be equal to the output voltage (VOUT). This is because when the external resistance becomes extremely large, it effectively blocks the flow of current in the circuit, causing all of the voltage to be dropped across the load and resulting in VB being equal to VOUT.

It is possible for a single conductor to have multiple values of resistance. This can happen if the conductor is made up of different materials or if it has varying cross-sectional areas along its length. The resistance of a conductor is determined by its length, cross-sectional area, and the resistivity of the material it is made of. Therefore, if any of these factors change, the resistance of the conductor will also change.

If there is no current flowing from a power source, it means that the circuit is open and there is no flow of electrons. In this case, the voltage difference between the terminals of the power source will be equal to the electromotive force (EMF) of the battery. The EMF represents the maximum potential difference that the battery can provide when no current is flowing. Therefore, the correct answer is "القوه الدافعه الكهربيه للبطاريه".

The correct answer is R=r. When the external resistance R is equal to the internal resistance r, the battery efficiency is 50%. This means that half of the energy provided by the battery is dissipated as heat in the internal resistance, while the other half is delivered to the external circuit. In this case, the battery is operating at its maximum efficiency point. If the external resistance is greater than the internal resistance (R>r), the battery efficiency will be less than 50%. If the external resistance is less than the internal resistance (R

The correct answer is "كفائه البطاريه". This is because the question is asking for the percentage relationship between the voltage difference across the battery terminals and its electromotive force. The efficiency of the battery is a measure of how well it converts chemical energy into electrical energy, and it is directly related to the percentage relationship between these two quantities.

The correct answer is "شده التيار" which translates to "current intensity" in English. This term refers to the amount of electric charge passing through a conductor per unit of time, measured in Amperes (A).

The correct answer is "حفظ الشحنة" (conservation of charge). Kirchhoff's first law, also known as Kirchhoff's current law, states that the total current entering a junction in an electrical circuit is equal to the total current leaving the junction. This law is based on the principle of conservation of charge, which states that charge cannot be created or destroyed, only transferred or redistributed. Therefore, the correct answer is "حفظ الشحنة" (conservation of charge).

When resistors are connected in parallel, the equivalent resistance is always smaller than the smallest individual resistance. This is because when resistors are in parallel, there are multiple paths for the current to flow through, resulting in a decrease in total resistance. In this case, one of the resistors has a value of 5 ohms, so the equivalent resistance will be smaller than 5 ohms.

The correct answer is "المقاومه الاوميه" which translates to "resistance in ohms." In electrical circuits, resistance is the measure of opposition to the flow of electric current. It is determined by the material and dimensions of the conductor. The greater the resistance, the smaller the current for a given voltage. Therefore, the ratio between the voltage difference across a conductor and the current flowing through it is represented by resistance in ohms.

The statement is false because the battery efficiency decreases as its internal resistance increases. A higher internal resistance leads to more energy loss within the battery, resulting in a lower overall battery efficiency. Therefore, as the internal resistance decreases, the battery efficiency increases.

The electrical cable is designed to have a low resistance in order to allow the flow of electric current without significant loss of energy. A low resistance helps to minimize the heat generated in the cable and ensures efficient transmission of electricity.

When two resistors are connected in parallel, the total resistance is given by the formula: 1/Rt = 1/R1 + 1/R2. In this case, one resistor has a resistance of 18 ohms and the other has a resistance of 9 ohms. They are connected in parallel with a length of 1/3L. Since the total resistance is given as 18 ohms, we can set up the equation: 1/18 = 1/18 + 1/9. Solving this equation, we find that the resistance of the second resistor is also 18 ohms. Therefore, the total resistance becomes 18 ohms.

The given options are different units of measurement. "جول" and "اوم.كلوم" are units of energy, "فولت" is a unit of electric potential, "ات" is a unit of electric current, "امبير" is also a unit of electric current, and "نيوتن ثانيه" is a unit of momentum. Among these options, "امبير" is the correct answer as it is the unit of electric current.

The equivalent resistance between A and B is 4 ohms.

In the given figure, there are four lights labeled N, M, L, and K. When the switch S is closed, it means that the circuit is completed and the current flows through the circuit. However, the light L is not connected to the circuit, so it does not receive any current and remains off. Therefore, the correct answer is that the light L turns off when the switch S is closed.

The statement is false because it is possible for the voltage difference between the terminals of a column to be greater than the voltage of the source. This can happen in cases where there is a voltage drop or loss in the circuit due to resistance or other factors.

The resistance of a conductor increases with an increase in temperature. This is because as the temperature rises, the atoms in the conductor vibrate more vigorously, causing more collisions with the free electrons and impeding their flow. As a result, the resistance of the conductor increases. Therefore, the statement that the resistance of a conductor decreases with an increase in temperature is false.

When the key is closed, the equivalent resistance decreases by half. Therefore, the resistance R must be equal to 14 ohms in order for the equivalent resistance to decrease by half.

The value of Rx can be determined using Ohm's law, which states that the voltage (V) across a resistor is equal to the current (I) flowing through it multiplied by its resistance (R). In this case, we are given the voltages V1 and V2, but we need to find the resistance Rx. Since the voltages are given in volts, we can assume that the current is in amperes. Therefore, we can rearrange the formula to solve for Rx: Rx = V/I. Using V1 = 40V and V2 = 24V, and assuming the current is the same for both voltages, we can calculate Rx as Rx = 40V/10A = 4Ω.

When the radius of the wire doubles, the current intensity increases fourfold.

When the current passing through a conductor doubles, its resistance remains constant.

The correct answer is "V-V1=V3" because it is the only equation that represents the correct relationship between the voltmeters. The equation states that the voltage measured by the first voltmeter (V1) subtracted from the total voltage (V) is equal to the voltage measured by the third voltmeter (V3). This equation implies that the total voltage is divided between the first and third voltmeters.

The equivalent resistance between A and B is equal to 4 ohms.

The correct answer is "المقاومه النوعيه" which translates to "specific resistance" in English. This term refers to the resistance of a material per unit length and cross-sectional area. In this context, it is stating that the resistance of a cube with a side length of 1 meter is being referred to as the specific resistance.

When the current passing through a conductor doubles, the voltage difference across it also doubles.

The statement is true because when resistors are connected in parallel, the total current flowing through the resistors is divided among them. According to Ohm's law, the current flowing through each resistor is inversely proportional to its resistance. Therefore, the resistor with the smallest resistance will have the highest current flowing through it.

The ratio between the readings of ammeter A1 and ammeter A2 in the given figure is 1/3.

The correct answer is 3. This means that the current intensity is equal to 3 amperes.

When resistors are connected in parallel, the total resistance decreases. According to Ohm's Law, the current drawn from a power source is inversely proportional to the resistance. Therefore, when the resistance decreases, the current drawn from the power source increases. Hence, the correct answer is False, the power drawn from a power source increases when a resistor is connected in parallel with another resistor in a circuit.

When the current flowing through a conductor doubles, the power consumed increases to four times its original value.

The given answer is .4. This implies that the reading of A2 is equal to 4.

The question states that the voltmeter reading is 9 volts. The voltmeter measures voltage, while the ammeter measures current. Therefore, the ammeter reading is not directly related to the voltmeter reading. Without any additional information or context, it is not possible to determine the ammeter reading.

If the two lamps are symmetrical, it means that they have the same brightness. Therefore, after closing the switch, the brightness of both lamps will remain constant.

When two equal resistors are connected in parallel, their total resistance is half of each individual resistor. Therefore, when the resistors are connected in series, their total resistance will be double the resistance of each individual resistor. The correct answer, "ربع" (quarter), represents the fact that the total resistance in series is four times smaller than the resistance of each individual resistor.

When the current passing through a conductor is doubled, the resistance value does not change.

The correct answer is "يضىء الثلاث مصابيح معا" which means "all three lamps light up together". This suggests that the three lamps are connected in parallel to the batteries. In a parallel circuit, each component has its own separate path to the power source, so when one lamp is turned on, it does not affect the others. Therefore, all three lamps can light up at the same time.

The voltage difference between points b and c is given as 3V. The voltage difference between points a and d can be found by subtracting the voltage difference between points b and c from the total voltage difference between points a and c. Therefore, the voltage difference between points a and d is 11V.