Question

4) Find the effective resistance when resistors 10 2 and 15 Q are
connected in (i) series, (ii) parallel. only for 9th std questions​

Answer 1

AnSwer :-

$\bigstar$The combined resistance of any number of resistance connected in series is equal to the sum of the individual resistance .i.e.,

$\bf{ R= R_1 + R_2 +R_3..... R_n}$

According to question

R₁ = 10Ω

R₂ = 15Ω

so,

➠ R = R₁ + R₂

➠ R = 10 + 15

➠ R = 25 Ω

thus,the equivalent resistance of the combination in series is 25 Ω

$\bigstar$the reciprocal of combined resistance of a number of resistance connected in parallel is equal to sum of the reciprocal of all the individual resistance .i.e.,

$\bf{ \dfrac{1}{R} = \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dfrac{1}{R_3} ..... \dfrac{1}{R_n} }$

According to question,

R₁ = 10Ω

R₂ = 15Ω

so,

$: \implies \tt{ \dfrac{1}{R} = \dfrac{1}{R_1} + \dfrac{1}{R_2} } \\ \\ : \implies \tt{ \dfrac{1}{R} = \dfrac{1}{10} + \dfrac{1}{15} } \\ \\ : \implies \tt{ \dfrac{1}{R} = \dfrac{3 + 2}{30} } \\ \\ : \implies \tt{ \dfrac{1}{R} = \dfrac{5}{30} } \\ \\ : \implies\tt R = \dfrac{30}{5} \\ \\ : \implies\tt R = 6 Ω$

thus, the equivalent resistance of the combination in parallel is 6Ω

$\:$

#sanvi...