Electricity Online Test 10th Science Lesson 4 Questions in English

The motion of what through a conductor (e.g., copper wire) will constitute an electric current?

Which among the following is the symbol that represent the Electric current?

If a net charge ‘Q’ passes through any cross section of a conductor in time ‘t’, then the current flowing through the conductor is _____

What is the SI unit of electric current?

A charge of 12 coulomb flows through a bulb in 5 second. What is the current through the bulb?

Which among the following component is used to fix the magnitude of the current through a circuit?

Which is used to select the magnitude of the current through a circuit?

Which among the following is used to detect the current and its direction?

Which among the following statement is correct An electric circuit is an open conducting loop (or) path, which has a network of electrical components through which electrons and protons are able to flow. This path is made using electrical wires so as to connect an electric appliance to a source of electric charges (battery). In this circuit, if the switch is ‘on’, the bulb glows. If it is switched off, the bulb does not glow. Therefore, the circuit must be closed in order that the current passes through it. The potential difference required for the flow of charges is provided by the battery. The electrons flow from the negative terminal to the positive terminal of the battery. By convention, the direction of current is taken as the direction of flow of positive charge (or) opposite to the direction of flow of electrons. Thus, electric current passes in the circuit from the positive terminal to the negative terminal.  

Which among the following component is used to measure the potential difference?

Which among the following components is wrongly matched with its unit

1. Ammeter – Used to measure the difference in current and voltage
2. A diode    – It is used in electronic devices
3. Ground connection – Used to provide protection to the electrical components. It also serves as a reference point to measure the electric potential

Which among the following statement is correct

1. In the conductor, the charges will flow from a point in it, which is at a lower electric potential to a point, which is at a higher electric potential.
2. In the conductor, the charges will flow from a point in it, which is at a higher electric potential to a point, which is at a lower electric potential.
3. There must be a difference in temperature between two points in a solid for the heat to flow in it. Similarly, a difference in electric potential is needed for the flow of electric charges in a conductor.

Which at a point is defined as the amount of work done in moving a unit positive charge from infinity to that point against the electric force?

Which among the following statement is correct

1. The electric potential difference between two points is defined as the amount of work done in moving a unit positive charge from one point to another point against the electric force.
2. Suppose, you have moved a charge Q from a point A to another point B. Let ‘W’ be the work done to move the charge from A to B. Then, the potential difference between the points A and B is given by the following expression: Potential Difference (V) = work done (W) / charge (Q).
3. Potential difference is inversely proportion to the difference in the electric potential of these two points. If V_A and V_B represent the electric potential at the points A and B respectively, then, the potential difference between the points A and B is given by: V = V_A – V_B (if V_A is less than V_B) V = V_B – V_A (if V_B is less than V_A).

The SI unit of electric potential or potential difference is ___

Which among the following equation defines 1 Volt?

Who among the following established the relation between the potential difference and current?

Which among the following statement is correct

1. According to Ohm’s law, at a constant temperature, the steady current ‘I’ flowing through a conductor is directly proportional to the potential difference ‘V’ between the two ends of the conductor. I is proportion to V. Hence, I / V = constant.  The value of this proportionality constant is found to be R. Therefore I = R V
2. V = I R. Here, R is a constant for a given material (say Nichrome) at a given temperature and is known as the resistance of the material. Since, the potential difference V is proportional to the current I, the graph between V and I is a straight line for a conductor.

The work done in moving a charge of 10 C across two points in a circuit is 100 J. What is the potential difference between the points?

Which can be defined as the ratio between the potential difference across the ends of the conductor and the current flowing through it?

Which among the following statement is correct

1. In this Figure, a Nichrome wire was connected between X and Y. If you replace the Nichrome wire with a copper wire and conduct the same experiment, you will notice a same current for the same value of the potential difference across the wire. If you again replace the copper wire with an aluminium wire, you will same value again for the current passing through it.
2. From equation V = I R, you have learnt that V/I must be equal to the resistance of the conductor used. The variations in the current for the same values of potential difference indicate that the resistance of different materials is different.
3. Resistance of a material is its property to oppose the flow of charges and hence the passage of current through it. It is different for different materials. From Ohm’s Law, V / I = R.

What is the SI unit of resistance?

Which among the following equation denotes Resistance of a conductor is said to be one ohm if a current of one ampere flows through it when a potential difference of one volt is maintained across its ends?

Which among the following is the unit of Electric resistivity?

Which among the following statement is correct

1. You can verify electric resistivity by doing an experiment that the resistance of any conductor ‘R’ is directly proportional to the length of the conductor ‘L’ and is inversely proportional to its area of cross section ‘A’. R LA. Therefore R = ρ (L/A)
2. ρ (rho) is a constant, called as electrical resistivity or specific resistance of the material of the conductor. ρ = (RA) / L. If L = 1 m, A = 1 m2 then, from the above equation ρ = R. Electrical resistivity of a conductor is a measure of the resisting power of a specified material to the passage of an electric current. It is a constant for a given material.

Calculate the resistance of a conductor through which a current of 2 A passes, when the potential difference between its ends is 30 V?

Which is a conductor with highest resistivity equal to 1.5 × 10^-6 Ω m?

The reciprocal of electrical resistivity of a material is called _____

The unit of Conductance is ____

Which among the following is the Insulator?

What is the unit of electrical conductivity?

Which among the following material materials resistivity is wrongly matched

1. Copper – 1.62 × 10^-8
2. Nickel – 10.14 × 10^–8
3. Chromium – 12.9 × 10^–8

The combination of resistors is known as ______

The resistance of a wire of length 10 m is 2 ohms. If the area of cross section of the wire is 2×10^-7 m², determine its (i) resistivity (ii) conductance and (iii) conductivity.

Which among the following statement is correct

1. A series circuit connects the components one after the other to form a ‘multiple loop’. A series circuit has two or more loop through which current can pass. If the circuit is interrupted at any point in the loop, no current can pass through the circuit and hence no electric appliances connected in the circuit will work.
2. Series circuits are commonly used in devices such as flashlights. Thus, if resistors are connected end to end, so that the same current passes through each of them, then they are said to be connected in series.

Which among the following statement is correct

1. Let, three resistances R1, R2 and R3 be connected in series (Figure 4.6). Let the current flowing through them be I. According to Joules Law, the potential differences V₁, V₂ and V₃ across R₁, R₂ and R₃ respectively, are given by V₁ = IR₁, V₂ = IR₂, V₃ = IR_3. The sum of the potential differences across the ends of each resistor is given by: V = V₁ + V₂ + V₃ ---->>> 1
2. Using equations, we get V = I R₁ + I R₂ + I R₃. The effective resistor is a single resistor, which can replace the resistors effectively, so as to allow the same current through the electric circuit. Let, the effective resistance of the series-combination of the resistors, be R_S. Then, V = I R_S. --->>> 2
3. Combining 1 and 2, I R_S = I R₁ + I R₂ + I R₃ i.e., R_S = R₁ + R₂ + R_3. Thus, you can understand that when a number of resistors are connected in series, their equivalent resistance or effective resistance is equal to the sum of the individual resistances. When ‘n’ resistors of equal resistance R are connected in series, the equivalent resistance is ‘n R’.

Three resistors of resistances 5 ohms, 3 ohm and 2 ohms are connected in series with 10 V battery. Calculate their effective resistance and the current flowing through the circuit?

Which among the following statement is correct

1. If you consider the connection of a set of parallel resistors that are connected in series, you get a series – parallel circuit. Let R1 and R2 be connected in parallel to give an effective resistance of RP1. Similarly, let R3 and R4 be connected in parallel to give an effective resistance of RP2. Then, both of these parallel segments are connected in series. 1 / R_p1 = (1 / R₁)+(1 / R₂); 1 / R_p2 = (1 / R₃)+(1 / R₄) Hence, R_Total = R_P1 + R_P2
2. If you consider a connection of a set of series resistors connected in a parallel circuit, you get a parallel-series circuit. Let R1 and R2 be connected in series to give an effective resistance of RS1. Similarly, let R3 and R4 be connected in series to give an effective resistance of RS2. Then, both of these serial segments are connected in parallel.

R_S1 = R₁ + R₂, R_S2 = R₃ + R_4. Hence, 1 / R_Total  = (1 / R_S1)+(1 / R_S2)

Which among the following is not the property of series circuit?

Which among the following is not the property of parallel circuit?

Which among the following statement is correct

1. Generally, a source of electrical energy can develop a potential difference across a capacitor, which is connected to that source. This potential difference constitutes a current through the capacitor. For continuous drawing of current, the source has to continuously spend its energy.
2. A part of the energy from the source can be converted into useful work and the rest will be converted into heat energy. Thus, the passage of electric current through a wire, results in the production of heat. This phenomenon is called heating effect of current. This heating effect of current is used in devices like electric heater, electric iron, etc.

Let ‘I’ be the current flowing through a resistor of resistance ‘R’, and ‘V’ be the potential difference across the resistor. The charge flowing through the circuit for a time interval ‘t’ is ‘Q’. The work done in moving the charge Q across the ends of the resistor with a potential difference of V is VQ. What is heat produced in resistor?

Which among the following does not states the joules law of heating that the heat produced in any resistor is

Which among the following is not the property of Nichrome which is used as the heating element?

How fuse wire is connected in an electric circuit, which when a large current pass through the circuit, the fuse wire melts due to Joule’s heating effect and hence the circuit gets disconnected?

In electric bulbs, a small wire made up of a material whose melting point is very high is used, known as ______

An electric heater of resistance 5 Ω is connected to an electric source. If a current of 6 A flows through the heater, then find the amount of heat produced in 5 minutes.

In general, what is defined as the rate of doing work or rate of spending energy?

Suppose a current ‘I’ flows through a conductor of resistance ‘R’ for a time ‘t’, then the potential difference across the two ends of the conductor is ‘V’. The work done ‘W’ to move the charge across the ends of the conductor is given by what equation?

The SI unit of electric power is _____

Which is a unit in the foot-pound-second (fps) or English system, sometimes used to express the electric power?

One horse power is equal to how many watts?

Which among the following statement is correct

1. Electricity is consumed both in houses and industries. Consumption of electricity is based on two factors: (i) Amount of electric power and (ii) Duration of usage. Electrical energy consumed is taken as the product of electric power and time of usage.
2. Consumption of electrical energy is measured and expressed in watt hour, though its SI unit is watt second. In practice, a larger unit of electrical energy is needed. This larger unit is kilowatt hour (kWh).
3. One kilowatt hour is otherwise known as one unit of electrical energy. One kilowatt hour means that an electric power of 100 watt has been utilized for an hour. Hence,

1 kWh = 100 watts hour = 100 × (60 × 60) watt second = 3.6 × 10⁵ J.

Which among the following statement is correct

1. The electricity produced in power stations is distributed to all the domestic and industrial consumers through overhead and underground cables. In our homes, electricity is distributed through the domestic electric circuits wired by the electricians.
2. The first stage of the domestic circuit is to bring the power supply to the main-box from a distribution panel, such as a transformer. The important components of the main-box are: (i) a fuse box and (ii) a meter. The meter is used to record the consumption of electrical energy. The fuse box contains either a fuse wire or a miniature circuit breaker (MCB).
3. The function of the fuse wire or a MCB is to protect the house hold electrical appliances from overloading due to excess current. An MCB is a switching device, which can be activated automatically as well as manually. It has a spring attached to the switch, which is attracted by an electromagnet when an excess current pass through the circuit. Hence, the circuit is broken and the protection of the appliance is ensured.

In India, domestic circuits are supplied with an alternating current of potential what?

In countries like USA and UK, domestic circuits are supplied with an alternating current of potential 110/120 V and frequency of what?

The electricity is brought to houses by how many insulated wires?

Out of the two Insulated wires brought to house, one wire has a red insulation and is called ____

Which among the following statement is correct

1. The electricity supplied to your house is actually an direct current having an electric potential of 220 V. Both, the live wire and the neutral wire enter into a box where the main fuse is connected with the live wire.
2. After the electricity meter, these wires enter into the main switch, which is used to discontinue the electricity supply whenever required. After the main switch, these wires are connected to live wires of two separate circuits. Out of these two circuits, one circuit is of a 5 A rating, which is used to run the electric appliances with a lower power rating, such as tube lights, bulbs and fans.
3. The other circuit is of a 15 A rating, which is used to run electric appliances with a high-power rating, such as air-conditioners, refrigerators, electric iron and heaters. It should be noted that all the circuits in a house are connected in parallel, so that the disconnection of one circuit does not affect the other circuit.

In which among the following circuit, each electric appliance gets an equal voltage?

The fuse wire or MCB will not disconnect the circuit in the event of what?

When a live wire comes in contact with a neutral wire, it causes what?

What happens when a large number of appliances are connected in series to the same source of electric power?

In domestic circuit which wire is used as third wire having a green insulation which is usually connected to the body of the metallic electric?

Two bulbs are having the ratings as 60 W, 220 V and 40 W, 220 V respectively. Which one has a greater resistance?

With the help of which chemical compounds, the manufacturer can produce LED bulbs that radiates red, green, yellow and orange colours?

Calculate the current and the resistance of a 100 W, 200 V electric bulb in an electric circuit?

Which among the following is incorrect about LED bulb?

1. As there is one large filament, there is less loss of energy in the form of heat. It is cooler than the incandescent bulb. It is not harmful to the environment. A wide range of colours is possible here.
2. In comparison with the fluorescent light, the LED bulbs have significantly low power requirement. It is cost-efficient and energy efficient. Mercury and other toxic materials are not required.

In the circuit diagram given below, three resistors R1, R2 and R3 of 5 Ω, 10 Ω and 20 Ω respectively are connected as shown. Calculate:

1. Current through each resistor ii) Total current in the circuit iii) Total resistance in the circuit

LEDs emitting which colour light are used in monochrome TV?

Which among the following colour LEDs are not used in colour television?

Which is the display device used to give an output in the form of numbers or text?

The first LED television screen was developed by whom in 1977?

Three resistors of 1 Ω, 2 Ω and 4 Ω are connected in parallel in a circuit. If a 1 Ω resistor draws a current of 1 A, find the current through the other two resistors?

Which among the following statement is correct

1. A parallel circuit has two or more loops through which current can pass. If the circuit is disconnected in one of the loops, the current can still pass through the other loop(s). The wiring in a house consists of parallel circuits. Consider that three resistors R₁, R₂ and R₃ are connected across two common points A and B.
2. The potential difference across each resistance is the same and equal to the potential difference between A and B. This is measured using the voltmeter. The current I arriving at A divides into three branches I₁, I₂ and I₃ passing through R₁, R₂ and R³ respectively. According to the Ohm’s law, you have, I₁ = V / R₁, I₂ = V / R₂, I₃ = V / R₃. The total current through the circuit is given by I = I₁ + I₂ + I₃ = V / R₁ + V / R₂ + V / R₃. --->>>
3. Let the effective resistance of the parallel combination of resistors be R_p. Then, I = V / R_p. combining 1 and 2 we have V / R_p = (V / R₁)+(V / R₂)+(V / R₃) → 1 / R_p = (1 / R₁)+(1 / R₂)+(1 / R₃). Thus, when a number of resistors are connected in parallel, the sum of the reciprocals of the individual resistances is equal to the reciprocal of the effective or equivalent resistance. When ‘n’ resistors of equal resistances R are connected in parallel, the equivalent resistance is n / R. Hence, R_P = n / R.