Electricity
21 solved questions from Class 10 Science, each with the full working. Tap any question to see the step-by-step solution.
- 1 A copper wire of length 2.0 m and cross‑sectional area 1.0×10^-6 m^2 has a resistivity of 1.68×10^-8 Ω m. Calculate its resistance. medium 2 marks Resistance using resistivity formula
- 2 A family uses a 1.5 kW electric iron for 2 hours daily. The cost of electricity is Rs. 8 per kilowatt‑hour. Calculate the monthly (30 days) electricity bill for using the iron. hard 4 marks Electrical energy consumption and cost
- 3 Which of the following statements correctly defines electric current? easy MCQ 1 mark Definition of electric current
- 4 A heater is connected to a 240 V mains supply and draws a current of 10 A. Calculate the resistance of the heater and the electrical power it consumes. medium 3 marks Ohm’s law and electric power
- 5 A resistor of resistance 5 Ω carries a current of 2 A. What is the potential difference across the resistor? easy MCQ 1 mark Ohm’s law (V = IR)
- 6 Write the expression for electrical power and state the unit of each quantity in the formula. easy 2 marks Power formula
- 7 Resistors R_1 = 3 Ω, R_2 = 6 Ω, and R_3 = 6 Ω are connected such that R_1 is in parallel with the series combination of R_2 and R_3. Find the equivalent resistance of the whole network. hard 5 marks Series‑parallel combination of resistors
- 8 A bulb rated at 60 W is operated on a 240 V mains supply. (a) Calculate the current drawn by the bulb. (b) Determine the resistance of the filament. medium 3 marks Power and resistance of appliances
- 9 Explain the working principle of a fuse in a domestic electric circuit and describe how it protects electrical appliances from damage. medium 4 marks Fuse as safety device
- 10 A domestic electric kettle is rated at 1500 W and is designed to operate on a 230 V supply. hard 5 marks Power, resistance and energy cost calculations
- 11 Explain how a circuit breaker differs from a fuse in providing protection to a domestic electric circuit. medium 2 marks Safety devices – fuse vs. circuit breaker
- 12 A copper wire has length 5 m and cross‑sectional area 2.5×10^-6 m^2. Given the resistivity of copper is 1.68×10^-8 Ω · m, calculate the resistance of the wire. medium 3 marks Resistance from resistivity
- 13 A resistor of resistance 8 Ω carries a current of 0.5 A. Calculate the potential difference across the resistor. easy 1 mark Ohm's law (V = I R)
- 14 What is the primary topic or theoretical principle explored in 'Electricity' (Class 10 SCIENCE)? medium MCQ Chapter Core Principle
- 15 Which key mechanism or analytical rule is highlighted in 'Electricity'? medium MCQ Key Analytical Mechanism
- 16 An electric resistor of resistance 12 Ω is connected across a 36 V supply. Calculate the electric current flowing through the resistor. easy 1 mark Ohm’s law
- 17 Three resistors of 4 Ω, 6 Ω and 10 Ω are connected in series across a 24 V supply. Find (i) the equivalent resistance, (ii) the current in the circuit, (iii) the voltage drop across each resistor, and (iv) the total power dissipated in the circuit. hard 4 marks Series circuit analysis
- 18 Which of the following statements correctly describes the function of a fuse in a domestic electrical circuit? easy MCQ 1 mark Electrical safety
- 19 A copper wire of length 3 m and cross‑sectional area 4×10^-6,m^2 has a resistivity of 1.68×10^-8,Ω!·!m. Calculate (i) the resistance of the wire at room temperature and (ii) the resistance if the temperature is lowered such that the resistivity decreases by 10%. hard 5 marks Resistivity and Temperature Dependence
- 20 An electric fan rated at 75 W operates for 5 h each day. If the electricity cost is Rs 10 per kWh, what is the total cost of running the fan for 30 days? hard 4 marks Energy Consumption
- 21 A 3 A current flows through a 6 Ω resistor. What is the potential difference across the resistor? easy MCQ 1 mark Ohm's Law