Electric circuits miscellaneous
-  The two electric sub-networks N1 and N2 are connected through three resistors as shown in the figure below. The voltage across 5 Ω resistor and 1 Ω resistor are given to be 10V and 5V respectively. Then voltage across 15 Ω resistor is 
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                        View Hint View Answer Discuss in Forum By KCL, if we take a cutset along all three branches, then total current at the junction is zero. 
 i.e. I 1 + I 2 + I 3 = 0⇒ 10 + I2 + 5 = 0 5 1 
 ⇒ I2 = 7A
 and V = – 105 V.Correct Option: ABy KCL, if we take a cutset along all three branches, then total current at the junction is zero. 
 i.e. I 1 + I 2 + I 3 = 0⇒ 10 + I2 + 5 = 0 5 1 
 ⇒ I2 = 7A
 and V = – 105 V.
-  In the given circuit, voltages V1 and V2 respectively are 
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                        View Hint View Answer Discuss in Forum I1 = 10 × 10– 3 V1 – 5 × 10– 3V2 
 100 = 25I1 + V1
 100 – V1 = 0.25V1 – 0.125 V2
 ⇒ 800 = 10 V2....(i)
 I 2 = 50 × 10– 3 V1 + 20 × 10– 3V2
 V2 = – 100 I2
 ∴ V2 = 5V1 – 2V2
 ⇒ 3V2 + 5V1 = 0 ....(ii)
 Solving equations (i) and (ii), we get
 V1 = 68.6 V, and V2 = – 114.3 VCorrect Option: BI1 = 10 × 10– 3 V1 – 5 × 10– 3V2 
 100 = 25I1 + V1
 100 – V1 = 0.25V1 – 0.125 V2
 ⇒ 800 = 10 V2....(i)
 I 2 = 50 × 10– 3 V1 + 20 × 10– 3V2
 V2 = – 100 I2
 ∴ V2 = 5V1 – 2V2
 ⇒ 3V2 + 5V1 = 0 ....(ii)
 Solving equations (i) and (ii), we get
 V1 = 68.6 V, and V2 = – 114.3 V
-  A T-network is shown in the given figure. Its Y matrix will be (units in siemens) 
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                        View Hint View Answer Discuss in Forum NA Correct Option: CNA 
-  The driving-point impedance of a one-port reactive network is given by
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                        View Hint View Answer Discuss in Forum For an L– C network, driving-point impedance function poles and zeros should alternate. This is satisfied by the function at (b) alone. Correct Option: BFor an L– C network, driving-point impedance function poles and zeros should alternate. This is satisfied by the function at (b) alone. 
-  In the circuit shown in the given figure, G12 = V2 = ? V1  
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                        View Hint View Answer Discuss in Forum I2 = y21V1 + y22V2 
 I2 = – V2 YL
 y21V1 + (y22 + YL )V2 = 0∴ V2 = -y21 V1 (y22 + yL) 
 Correct Option: BI2 = y21V1 + y22V2 
 I2 = – V2 YL
 y21V1 + (y22 + YL )V2 = 0∴ V2 = -y21 V1 (y22 + yL) 
 
 
	