Question

can someone help pls!!

Answer 1

Answer:

Rp = 10 Ohms; I = 0.9 Amps

Explanation:

Since, there are two resistors each with 20Ω connected in parallel, the total resistance of the combination (Rp) of the circuit is as follows:

i.e 1/Rp = (1/R1 + 1/R2)

1/Rp = (1/20Ω + 1/20Ω)

1/Rp = (1 + 1)/20Ω

1/Rp = 2/20Ω

1/Rp = 1/10Ω

To get the value of Rp, cross multiply

Rp x 1 = 10Ω x 1

Rp = 10Ω

Apply the formula

Voltage V = Current I x Total resistance Rp

I = V/Rp

I = 9V/10Ω

I = 0.9 Amps

Thus, the total resistance is 10 Ohms, the current through the ammeter is 0.9 Amps

Answer 2

Answer :

• Total resistance is 10Ω
• Current through the ammeter is of 0.9 A

Explaination :

As we know that, if n resistances R1 , R2 and R3 .... Rn are joined in parallel the equivalent resistance is given as :

$\boxed{ \sf{ \dfrac{1}{R_p} \: = \: \dfrac{1}{R_1}\: + \: \dfrac{1}{R_2} \: + \: \dfrac{1}{R_3} \: \: .... \: \dfrac{1}{R_n} }}$

R1 = 20Ω

R2 = 20Ω

Putting the values,

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \dfrac{1}{20Ω}\: + \: \dfrac{1}{20Ω}}$

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \dfrac{1 \times 1}{20}\: + \: \dfrac{1 \times 1}{20}}$

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \: \dfrac{1 \: + \: 1}{20}}$

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \: \dfrac{2}{20}}$

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \: \cancel\dfrac{2}{20}}$

$: \longmapsto \: \sf{ \dfrac{1}{R_p} \: = \: \dfrac{1}{10}}$

$: \longmapsto \: \pink{\bf{R_p\: = \: 10Ω }}$

Current through the ammete:-

As we know that,

• $\boxed{ \sf{I \: = \: \frac{V}{R } }}$

Here ,

• I is current
• V is Volts
• R is resistance

Putting the values,

$\longmapsto \: \sf{I \: = \: \dfrac{9}{10 } }$

$\longmapsto \: \red{\bf{I \: = \: 0.9}}$