# Recent questions tagged frequency

Draw the diagram and explain the working of ferrodynamic type frequency meter.

List the different types of frequency meters.

Explain working of Weston type frequency meter.

State the application of phase sequence indicator; clip on ammeter, frequency meter & P.F. meter.

List two types of oscillator, which generates frequency in RF range.

State the need of multistage amplifier. Draw frequency response of R-C coupled amplifier.

Classify the transformers based on the construction, frequency and power.

Define: 1) frequency, 2) cycle, 3) time period, 4) amplitude

A pulse radar has a pulse repetition frequency (PRF) of 3 KHz. If the radar is emitting at 10 GHz, what is the maximum unambiguous range for this radar? A) 5 Km B) 5 m C) 50 Km D) 15 m

A pulse compression radar transmits an encoded pulse having a frequency chirp from 990 MHz to 1010 MHz centred around 1 GHz. The range resolution capability of this radar is A) 7.5 m B) 7.5 Km C) 75 m D) 750 m

The clock frequency of an 8085 microprocessor based system is 3 MHz. What should be the minimum pulse width of the INTR signal so that it is recognized successfully? A) 5.6 µs B) 5.7 µs C) 5.8 µs D) 5.9 µs

What is the frequency range of VHF electromagnetic waves? A) 30-300 kHz B) 30-3000 kHz C) 30-300 MHz D) 30-3000 MHz

The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz

Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO

In a series R-C circuit, with the increase in frequency, current (A) Reduces (B) Increases (C) Does not change (D) Becomes zero

A series R-L-C Circuit has a resonant frequency of 1000 Hz. If the values of R, L and C are doubled, the new resonant frequency is

What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage:  (A) Eddy Current and Hysteresis losses will be excessive  (B) Current will be too much high  (C) Transformer may start to smoke and burn  (D) No effect

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

For measurement of radio frequency ac signals __________ type meter is used

In a series RLC high Q circuit, the current peaks at a frequency  (1) equal to the resonant frequency (2) greater than the resonant frequency (3) less than the resonant frequency (4) equal to half the resonant frequency

In a self-controlled synchronous motor fed from a variable frequency inverter  (1) the rotor poles invariably have damper windings  (2) there are stability problems  (3) the speed of the rotor decides stator frequency  (4) the frequency of the stator decides the rotor speed

For a 500 Hz frequency excitation, a 50 km long power line will be modeled as

What is the frequency of an alternator which has 2 poles and makes 3600 revolutions per minute? A) 3600 HZ B) 60 Hz C) 120 Hz D) None of these

What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known

The device which allows reverse power flow and withstands highest switch frequency is (A) GTO (B) MOSFET (C) IGBT (D) Inverter grade SCR

The time period of third harmonic of power supply frequency, in milliseconds, is (A) 20 (B) 3.33 (C) 6.66 (D) 60

Two waves have frequency of 500 Hz. One is set at its maximum value whereas the other at zero. The phase angle between them will be

A 4 GHz carrier is amplitude modulated by a low-pass signal of maximum cut off frequency 1 MHz. lf this signal is to be ideally sampled, the minimum sampling frequency should be nearly

In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the (A) applied load (B) internal compensation (C) impedance of the source (D) power dissipation in the chip

An accelerometer has input range of 0 to 10g, natural frequency 30 Hz and mass 0.001 kg. The range of the secondary displacement transducer in mm required to cover the input range is (A) 0 to 2.76 (B) 0 to 9.81 (C) 0 to 11.20 (D) 0 to 52.10

The frequency of an alternating current is?

The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of?

In a series L-C circuit at the resonant frequency the?

In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of?

For a frequency of 200 Hz, the time period will be?

Two waves of the same frequency have opposite phase when the phase angle between them is?

The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?

For given applied voltage, with the increase in frequency of the applied voltage?

Is the speed of alternator is directly proportional to frequency?

Which capacitor is used for high frequency?