15 Electricity Questions (Class 10) - PDF

# 15 Most Expected Questions - Class 10 ## Numericals **Q. 1.** A cylindrical conductor of length ‘l’ and uniform area of cross-section ‘A’ has resistance ‘R’. The area of cross-section of another conductor of the same material and same resistance but of length ‘2l’ is: a) A/2 b) 3A/2 c) 2A d) 3...

# 15 Most Expected Questions - Class 10 ## Numericals **Q. 1.** A cylindrical conductor of length ‘l’ and uniform area of cross-section ‘A’ has resistance ‘R’. The area of cross-section of another conductor of the same material and same resistance but of length ‘2l’ is: a) A/2 b) 3A/2 c) 2A d) 3A **CBSE OD. Set 1, 2020** **Q. 2.** The maximum resistance which can be made using four resistors each of resistance 1/2 Ω is: a) 2 Ω b) 1 Ω c) 2.5 Ω d) 8 Ω **CBSE OD. Set 1, 2020** **Q. 3.** Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the 40 W bulb will be: a)0.4 A b) 0.6 A c) 0.8 A d) 1 A **CBSE OD. Set 1, 2020** **Q. 4.** Show how would you join three resistors, each of resistance 9 Ω so that the equivalent resistance of the combination is 6 Ω? **CBSE 2018** **Q. 5.** For the combination of resistors shown in the following figure, find the equivalent resistance between M & N. **CBSE OD, Set 1, 2020** **Diagram**: A circuit diagram with points M and N connected via 4 resistors. Resistors R1, R2 and R3 connect directly between M and N, with R4 connecting between the junctions of R1 and R2, and R3 and R4. **Q. 6.** A torch bulb is rated 5 V and 500 mA. Calculate its a) Power. b) Resistances **CBSE OD, Set 2, 2020** **Q. 7 (a)** An electric bulb is rated at 200 V;100 W. What is its resistance? **CBSE OD, Set 3, 2020** **Q. 7 (b)** Calculate the energy consumed by 3 such bulbs if they glow continuously for 10 hours for complete month of November. **CBSE OD, Set 3, 2020** **Q. 9.** When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 Ma in the circuit. Find the value of the resistance of the resistor. **9th | 10th** **Q. 10.** V-I graph of two wires A and B are shown in the figure. If both wires are of the same length and same thickness, which of the two is made of a material of high resistivity? **CBSE 2014** **Diagram:** V-I graph, with A and B as the lines. Line A has a steeper slope than line B. **Q. 11.** You have three resistors of R Ω each and a battery of E volts. How would you connect these resistors with the battery to obtain maximum current? Draw a circuit diagram to illustrate your answer and also calculate the current drawn from the battery. **CBSE Term 1, Set 1, 2016** **Diagram:** All 3 resistors are in parallel with each other, in series with a battery. **Q. 12.** Two wires A and B are of equal length and have equal resistance. If the resistivity of A is more than that of B which wire is thicker and why? **CBSE 2014** **Diagram:** A rectangle labelled A, and a larger rectangle labelled B. **Q. 13.** Find the current flowing through the following electric circuit. Find the voltage drop across 3 Ω resistor. **CBSE 2013** **Diagram:** A circuit with a battery and 5 resistors. - Two resistors in series (3.6 Ω and 6 Ω) - Two resistors in parallel (1 Ω and 3 Ω) - One resistor in series with the parallel pair (3 Ω) **Q. 14.** Find the current drawn from the battery by the network of four resistors shown in the figure. **CBSE, Term 1 Set 1, 2015** **Diagram:** A square with 4 resistors of 10 Ω each. A battery is connected in series with one of the resistors. **Q. 15.** A given length of a wire is doubled on itself and this process is repeated once again. By what factor does the resistance of the wire change? **Diagram:** A diagram showing a wire of A being doubled on itself to create 2A, and then doubled again to create 4A.