Virtual Labs

In a transistor Hartley oscillator

a: Capacitive feedback is used Explanation

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b: Inductive feedback is used Explanation

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c: Entire coil is in the output circuit Explanation

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d: Resistive feedback is used Explanation

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The feedback signal in which of the following oscillator is derived from an inductive voltage divider in the LC circuit

a: Hartley Oscillator Explanation

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b: Weins bridge oscillator Explanation

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c: Colpitts Oscillator Explanation

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d: Phase shift Oscillator Explanation

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One condition for positive feedback is that the phase shift around the feedback loop must be

a: 45 Explanation

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b: 90 Explanation

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c: 180 Explanation

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d: 0 Explanation

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What type of sine-wave oscillator uses a tapped inductor to provide the positive feedback required for oscillation?

a: Clap Oscillator Explanation

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b: Colpitts Oscillator Explanation

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c: Hartley Oscillator Explanation

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d: Pierce Oscillator Explanation

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What type of capacitor is usually used in the tuned circuits of oscillators?

a: Electrolytic Explanation

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b: Surface mount Explanation

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c: High voltage Explanation

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d: Low loss Explanation

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For sustaining oscillations in an oscillator

a: Feedback factor should be negative and phase shift should be 0 or nπ Explanation

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b: Phase shift should be unity and phase shift should be 0 or π/2 Explanation

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c: Phase shift should be negative and phase shift should be 0 or π/2 Explanation

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d: Feedback factor should be unity and phase shift should be 0 or nπ Explanation

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Choose the right answer for Barkhausen criteria

a: βA = +1 Explanation

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b: βA = 0 Explanation

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c: βA = -1 Explanation

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d: β = A Explanation

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Which of the following factors do not affect the frequency stability of an oscillator?

a: Inter-element capacitances and stray capacitances Explanation

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b: Coil size Explanation

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c: Temperature variation Explanation

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d: Output load Explanation

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In Hartley oscillator, the expression for frequency of oscillation is given by

a: f = 1 / (2πRC√6) Explanation

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b: f = 1 / (2π√(LC)) with L = L₁ + L₂ Explanation

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c: f = 1 / (2π√(LC)) with C = (C₁ × C₂) / (C₁ + C₂) Explanation

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d: f = 1 / (2π√(R₁ × R₂ × C₁ × C₂)) Explanation

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