✓ Board-verified
Science · 2025 · 3 marks
CBSE 2025 · Region 1 · Set 1 · Q32
Consider the following electric circuit: Calculate the values of the following: (a) The total resistance of the circuit (b) The total current drawn…
Consider the following electric circuit :
Calculate the values of the following :
(a)
The total resistance of the circuit
(b)
The total current drawn from the source
(c)
Potential difference across the parallel combination of $\displaystyle 10 \Omega$ and $\displaystyle 15 \Omega$ resistors
Marking-scheme solution
(a)
\(\displaystyle \frac{1}{R_{1}}=\frac{1}{10 \Omega}+\frac{1}{15 \Omega}=\frac{1}{6 \Omega} \Rightarrow \mathrm{R}_{1}=6 \Omega\)
\(\displaystyle \frac{1}{R_{2}}=\frac{1}{60 \Omega}+\frac{1}{40 \Omega}=\frac{100}{2400 \Omega} \Rightarrow \mathrm{R}_{2}=24 \Omega\)
\(\displaystyle \because \mathrm{R}_{1}\) and \(\displaystyle \mathrm{R}_{2}\) are in series
\(\displaystyle \therefore \mathrm{R}_{\text {total }}=\mathrm{R}_{1}+\mathrm{R}_{2}=(6+24)=30 \Omega\)
(b)
\(\displaystyle \mathrm{V}=\mathrm{IR} \Rightarrow \mathrm{I}=\frac{V}{R}=\frac{15 V}{30 \Omega}=0.5 \mathrm{~A}\)
(c)
\(\displaystyle \mathrm{V}=\mathrm{IR}_{1}=0.5 \mathrm{~A} \times 6 \Omega=3.0 \mathrm{~V}\)
More from Electricity
- (i) Consider the following electric circuit: Calculate the values of the following: (I) Total resistance of the circuit. (II) The total electric…2026
- A 2000 W heater has a resistance of about 25 Ω, whereas a 100 W bulb has a resistance of 500 Ω. When 220 V is applied on these, then which of the two…2024
- Show how you would connect three resistors each of resistance 6 Ω, so that the combination has a resistance of 9 Ω. Also justify your answer. OR In…2024
- In domestic electric circuits the wiring with 15 A current rating is for the electric devices which have2023
- Assertion: Electrons move from lower potential to higher potential in a conductor. Reason (R): A dry cell maintains electric potential difference…2024
- (i) State whether the currents and potential difference in all the bulbs will be same or different when in a circuit three bulbs of: same wattage are…2024
- Consider two lamps A and B of rating 50 W; 220 V and 25 W; 220 V respectively. Find the ratio of the resistances of the two lamps (i.e. R_A: R_B ).…2025
- Study the given electric circuit in which 2 A electric current is flowing between points X and Y. (i) Using the battery, key, voltmeter and ammeter…2026
CBSE Class 10 Science past-paper question from the 2025 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.