Physics 9702 · AS & A Level · Rectification and smoothing

Rectification and smoothing — practice question

Fig. 6.1 illustrates a circuit that rectifies an alternating input voltage $V_{IN}$ and gives an output voltage $V_{OUT}$ across a resistor $R$. The rectification circuit has four terminals named W, X, Y and Z. A capacitor $C$ is placed in parallel with resistor $R$.
(a(i))[1]

State what is meant by rectification.

(a(ii))[1]

State the purpose of capacitor $C$.

(b(i))[2]

The change of $V_{IN}$ with $t$ may be written as $V_{IN} = A \cos Bt$ where $A$ and $B$ are constants. Find the values of $A$ and $B$. Include a unit with your answer for $A$.

(b(ii))[1]

Determine the type of rectification produced by the circuit in Fig. 6.1.

(b(iii))[2]

On Fig. 6.3, draw the circuit diagram for the components inside the rectification circuit.

(b(iv))[3]

Determine a value for the time constant for the discharge of the capacitor $C$ through the resistor $R$ in Fig. 6.1.

(i)[2]

The change of $V_{IN}$ with $t$ may be written as $V_{IN} = A \cos Bt$, where $A$ and $B$ are constants. Find the values of $A$ and $B$. Include a unit with your answer for $A$.

(ii)[1]

Determine the type of rectification produced by the circuit in Fig. 6.1.

(iii)[2]

On Fig. 6.3, draw the circuit diagram for the components inside the rectification circuit.

(iv)[3]

Determine a value for the time constant for the discharge of the capacitor $C$ through the resistor $R$ in Fig. 6.1.

(c)[2]

The capacitor $C$ has a capacitance of 570\,\mu\text{F}. Use your answer in (b)(iv) to find the resistance of resistor $R$.

Worked solution & mark scheme

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