The unit for expressing electric power is:
- AVolt.
- BJoule.
- CCoulomb.
- ✓Watt.
Answer: D.
View full solution →Question types
Electricity question types
334 questions across 7 question groups — pick any mix to generate a Science paper with step-by-step answer keys.
334
Questions
7
Question groups
5
Question types
01
M.C.Q
57 Q→02Answer the following questions:[1 M]
103 Q→03Answer the following questions: [2 M]
76 Q→04Answer the following questions: [3 M]
62 Q→05Answer the following questions: [5 M]
25 Q→06Fill in the blanks.
6 Q→07Case study.
5 Q→Sample Questions
Electricity questions
One sample from each question group in this chapter. Select any group above to see the full set with answer keys.
When a $4 \Omega $ resistor is connected across the terminals of a $12V$ battery, the number of coulombs passing through the resistor per second is:
- A$0.3$
- ✓$3$
- C$4$
- D$12$
Answer: B.
View full solution →In the circuit shown below:
The potential difference across the $3 \Omega $ resistor is:
The potential difference across the $3 \Omega $ resistor is:
- A$\frac{1}{9}\text{V}$
- B$\frac{1}{2}\text{V}$
- ✓$1V$
- D$2V$
Answer: C.
View full solution →The current passing through an electric kettle has been doubled. The heat produced will become:
- AHalf.
- BDouble.
- CFour time.
- ✓One$-$fourth.
Answer: D.
View full solution →A battery and three lamps are connected as shown? Which of the following statements about the currents at $X, Y$ and $Z$ is correct?
- AThe current at $Z$ is greater than that at $Y.$
- ✓The current at $Y$ is greater than that at $Z.$
- CThe current at $X$ equals the current at $Y.$
- DThe current at $X$ equals the current at $Z.$
Answer: B.
View full solution →Why should the resistance of:
A voltmeter be very large?
A voltmeter be very large?
What happens to the resistance as the conductor is made thinner?
A resistance of 20 ohms has a current of 2 amperes flowing in it. What potential difference is there between its ends?
An electric bulb is rated at 220V, 100W. What is its resistance?
An electric lamp is labelled 12V, 36W. This indicates that it should be used with a 12V supply. What other information does the label provide?
If five resistances, each of value $0.2$ ohm, are connected in series, what will be the resultant resistance?
View full solution →An electric room heater draws a current of 2.4A from the 120V supply line. What current will this room heater draw when connected to 240V supply line?
An electric bulb is connected to a 220V power supply line. If the bulb draws a current of 0.5A, calculate the power of the bulb.
What is meant by the heating effect of current? Give two applications of the heating effect of current.
A heating coil has a resistance of $200\Omega $. At what rate will heat be produced in it when a current of $2.5\ A $flows through it?
View full solution →State three factors on which the heat produced by an electric current depends. How does it depend on these factors?
Consider the circuit given below where A, B and C are three identical light bulbs of constant resistance.
- List the bulbs in order of increasing brightness.
- If C burns out, what will be the brightness of A now compared with before?
- If B burns out instead, what will be the brightness of A and C compared with before?
The electrical resistivities of four materials P, Q, R and S are given below:
$\begin{matrix}\text{P}&6.84\times10^{-8}\Omega\text{m}\\\text{Q}&1.70\times10^{-8}\Omega\text{m}\\\text{R}&1.0\times10^{15}\Omega\text{m}\\\text{S}&11.0\times10^{-7}\Omega\text{m}\end{matrix}$
Which material will you use for making:
View full solution →$\begin{matrix}\text{P}&6.84\times10^{-8}\Omega\text{m}\\\text{Q}&1.70\times10^{-8}\Omega\text{m}\\\text{R}&1.0\times10^{15}\Omega\text{m}\\\text{S}&11.0\times10^{-7}\Omega\text{m}\end{matrix}$
Which material will you use for making:
- Heating element of electric iron.
- Connecting wires of electric iron.
- Covering of connecting wires?
Calculate the resistance of a copper wire 1.0km long and 0.50mm diameter if the resistivity of copper is $1.7\times10\Omega\ \text{m}.$
View full solution →A $4 Ω$ coil and a $2 Ω$ coil are connected in parallel. What is their combined resistance? A total current of 3A passes through the coils. What current passes through the $2 Ω$ coil?
View full solution →A 5V battery is connected to two $20 Ω$ resistors which are joined together in series.
View full solution →- Draw a circuit diagram to represent this. Add an arrow to indicate the direction of conventional current flow in the circuit.
- What is the effective resistance of the two resistors?
- Calculate the current that flows from the battery.
- What is the p.d. across each resistor?
The circuit diagram given below shows the combination of three resistors $R_1, R_2$ and $R_3$:
Find:
View full solution →Find:
- Total resistance of the circuit.
- Total current flowing in the circuit.
- The potential difference across $R.$
In the circuit diagram given below five resistances of $10 Ω, 40 Ω, 30 Ω, 20 Ω\ \text{and}\ 60 Ω$ are connected as shown to a $12V$ battery.
Calculate:
View full solution →Calculate:
- Total resistance in the circuit.
- Total current flowing in the circuit.
State whether an electric heater will consume more electrical energy or less electrical energy per second when the length of its heating element is reduced. Give reasons for your answer.
With the help of a circuit diagram, deduce the equivalent resistance of two resistances connected in series. Two resistances are connected in series as shown in the diagram:
View full solution →- What is the current through the $5$ ohm resistance$?$
- What is the current through $R?$
- What is the value of $R?$
- What is the value of $ V?$
Fill in the following blanks with suitable words:
Copper is a good _______ Plastic is an _______.
Copper is a good _______ Plastic is an _______.
Fill in the following blanks with suitable words:
Current is measured in __________ using an __________ placed in __________ in a circuit.
Current is measured in __________ using an __________ placed in __________ in a circuit.
Fill in the following blanks with suitable words:
Potential difference is measured in __________ by using a __________ placed in __________ across a component.
Potential difference is measured in __________ by using a __________ placed in __________ across a component.
Fill in the following blanks with suitable words:
A current is a flow of _________ For this to happen there must be a _________.
A current is a flow of _________ For this to happen there must be a _________.
Fill in the following blank with a suitable word:
Ohm’s law states a relation between potential difference and ________.
Ohm’s law states a relation between potential difference and ________.
A boy noted the readings on his home’s electricity meter on Sunday at 8AM and again on Monday at 8AM (see figure below).
- What was the meter reading on Sunday?
- What was the meter reading on Monday?
- How many units of electricity have been used?
- In how much time these units have been used?
- If the rate is Rs. 5 per unit, what is the cost of electricity used during this time?
A student made an electric circuit shown here to measure the current through two lamps.
- Are the lamps in series or parallel?
- The student has made a mistake in this circuit. What is the mistake?
- Draw a circuit diagram to show the correct way to connect the circuit. Use the proper circuit symbols in your diagram.
Consider the circuits given below:
- In which circuit are the lamps dimmest?
- In which circuit or circuits are the lamps of equal brightness to the lamps in circuit?
- Which circuit gives out the maximum light?
The table below shows the current in three different electrical appliances when connected to the 240V mains supply:
| Appliance | Current |
| Kettle | 8.5A |
| Lamp | 0.4A |
| Toaster | 4.8A |
- Which appliance has the greatest electrical resistance? How does the data show this?
- The lamp is connected to the mains supply by using a thin, twin-cored cable consisting of live and neutral wires. State two reasons why this cable should not be used for connecting the kettle to the mains supply.
- Calculate the power rating of the kettle when it is operated from the 240V mains supply.
- A man takes the kettle abroad where the mains supply is 120V. What is the current in the kettle when it is operated from the 120V supply?
The figure given below shows an electric circuit in which current flows from a $6V$ battery through two resistors.
View full solution →- Are the resistors connected in series with each other or in parallel?
- For each resistor, state the p.d. across it.
- The current flowing from the battery is shared between the two resistors. Which resistor will have bigger share of the current?
- Calculate the effective resistance of the two resistors.
- Calculate the current that flows from the battery.
Generate a Electricity paper free
Pick question groups from the list above, set marks and difficulty, and export a branded PDF with step-by-step answer keys. First 3 chapters free — no signup.