Question

In an LCR series circuit, the voltages across R,
L and C at resonance are 40 V, 60 V and 60 V
respectively. The applied voltage is
1) 60v
240v
3) 160
V
4
) }(40)? +(120) v​

Answer 1

Answer:

V = 40V

Explanation:

Given, Vr = 40V ; Vl = 60V ; Vc = 60V

Formula:

V = √(Vr)² + (Vl - Vc)²

V = √40² + (60-60)²

V = 40V

At resonance, Z= R, Voltage applied will be equal to voltage across resistor. We can find the solution just by seeing the question.

Thank You.

Answer 2

Answer:

In an LCR series circuit, the voltages across R, L and C at resonance are 40 V, 60 V and 60 V respectively. The applied voltage is  40V

Explanation:

In the question, it is given that,

Voltage across resistor ($V_R$) = $40 V$

Voltage across inductor ($V_L$) = $60 V$

Voltage across capacitor ($V_C$) = $60 V$

For an LCR circuit,

The total voltage applied across the combination or the effective voltage can be calculated by the equation,

$\left\mathrm{V}_{\mathrm{eff}}\right=\sqrt{\mathrm{V}_{\mathrm{R}}^{2}+\left(\mathrm{V}_{\mathrm{L}}-\mathrm{V}_{\mathrm{C}}\right)^{2}}$     ...(1)

Since, $V_{L}-V_{C}=60-60 = 0$

$\left\mathrm{V}_{\mathrm{eff}}\right=\sqrt{\mathrm{{V}_{\mathrm{R}}}^{2}}$

Substitute values into above equation,

$\left\mathrm{V}_{\mathrm{eff}}\right=\sqrt{40^{2} } =40 V$

At resonance, The applied voltage will be equal to the  voltage across the Resistor.     

Hence second option is the correct answer.