Question:
When the input to Q is a 1 level, the frequency of oscillations of the timer circuit is _______.
When the input to Q is a 1 level, the frequency of oscillations of the timer circuit is _______.
Show Hint
555 timer oscillation freq = \( \frac{1.44}{(R_A + 2R_B)C} \) in astable mode. Easy to memorize!
Updated On: Jun 24, 2025
- \( \frac{1.44}{(R_A + 2R_B)C} \)
- \( \frac{1.44}{(R_A + R_B)C} \)
- \( \frac{1.44}{(2R_A + R_B)C} \)
- \( \frac{1.44}{(R_B + 2R_A)C} \)
Hide Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: 555 Timer in Astable Mode
In astable mode, the 555 timer continuously oscillates. The frequency of oscillation is determined by two resistors and a capacitor.
Step 2: Formula for Frequency
\[ f = \frac{1.44}{(R_A + 2R_B)C} \] This formula arises due to:
- \( T_{high} = 0.693 (R_A + R_B)C \)
- \( T_{low} = 0.693 R_B C \)
Step 3: Calculate
\[ T = T_{high} + T_{low} = 0.693 (R_A + 2R_B)C \Rightarrow f = \frac{1.44}{(R_A + 2R_B)C} \] Conclusion:
Option (1) is correct — it’s the standard 555 timer frequency formula in astable mode.
In astable mode, the 555 timer continuously oscillates. The frequency of oscillation is determined by two resistors and a capacitor.
Step 2: Formula for Frequency
\[ f = \frac{1.44}{(R_A + 2R_B)C} \] This formula arises due to:
- \( T_{high} = 0.693 (R_A + R_B)C \)
- \( T_{low} = 0.693 R_B C \)
Step 3: Calculate
\[ T = T_{high} + T_{low} = 0.693 (R_A + 2R_B)C \Rightarrow f = \frac{1.44}{(R_A + 2R_B)C} \] Conclusion:
Option (1) is correct — it’s the standard 555 timer frequency formula in astable mode.
Was this answer helpful?
0
0
Top Questions on Electric circuits and fields
The bus impedance matrix of a 4-bus power system is given.
A branch having an impedance of \( j0.2 \Omega \) is connected between bus 2 and the reference. Then the values of \( Z_{22,new} \) and \( Z_{23,new} \) of the bus impedance matrix of the modified network are respectively _______.
- AP PGECET - 2025
- Electrical Engineering
- Electric circuits and fields
The logic circuit given below converts a binary code \(Y_1, Y_2, Y_3\) into _______.
- AP PGECET - 2025
- Electrical Engineering
- Electric circuits and fields
The bus admittance matrix of the network shown in the given figure, for which the marked parameters are per unit impedance, is _______.
- AP PGECET - 2025
- Electrical Engineering
- Electric circuits and fields
- In an AC circuit the voltage applied is $v = 230\sin(\omega t - 30^\circ)$ volts. If the current flowing is $i = 47\sin(\omega t + 10^\circ)$ amps, then the current _______.
- AP PGECET - 2025
- Electrical Engineering
- Electric circuits and fields
- The impedance of a circuit is 10 ohms. If the inductive susceptance is 1 S, then inductive reactance of the circuit is_______.
- AP PGECET - 2025
- Electrical Engineering
- Electric circuits and fields
View More Questions
Questions Asked in AP PGECET exam
- Using Newton-Raphson method to solve $f(x) = e^{-x} - x$ with initial guess $x_0 = 0$, find the next iteration.
- AP PGECET - 2025
- Numerical Methods
- The solution of the differential equation
\[ (D^3 - 5D^2 + 7D - 3)y = e^{-2x} \] is:- AP PGECET - 2025
- Differential Equations
- If $I = \frac{1}{2\pi i} \oint \frac{z e^{1/z}}{z} \, dz$ in the unit circle $|z| = 1$, then:
- AP PGECET - 2025
- Calculus
- The given differential equation
$(x y^2 + n x^2 y) dx + (x^3 + x^2 y) dy = 0$ is exact when $n =$- AP PGECET - 2025
- Differential Equations
- If \( A = \begin{pmatrix} 1 & -1 \\ 2 & 3 \end{pmatrix} \) is a \( 2 \times 2 \) matrix, then the eigenvalues of the matrix \( 2A^2 - 4A + 5I \) are ______, where \( I \) is the \( 2 \times 2 \) unit matrix.
View More Questions