Physics Test - 27

In β-emission, a neutron of nucleus decays into a proton and a β-particle.

The reaction given as:

An oscillator is considered as an amplifier with positive feedback. It converts direct current from a power supply to an alternating current signal. It produces an alternating waveform without any input.

An Integrated circuit (IC) is an assembly of electronic components, fabricated as a single unit, in which miniaturized active devices and passive devices and their interconnections are built upon a thin substrate of semiconductor material. There are about 600 different types of Integrated circuits.

To transmit music, an approximate bandwidth of 20 kHz is required because of the high frequencies produced by the musical instruments. The audible range of frequencies extends from 20 Hz to 20 kHz.

Amplitude modulation (AM) is used for broadcasting because it avoids receiver complexity. Moreover, only a diode and a capacitor are sufficient to separate the audio signal from the amplitude-modulated wave.

After one half-life, N/2 sample remains and N/2 decays. After two half-lives, N/4 sample remains and N/4 decays out of the remaining N/2 sample. After three half-lives, N/8 sample remains and N/8 sample decays out of the remaining N/4 sample.
So, after three half-lives, in total, N/2 + N/4 + N/8 = 7N/8 decay happens. Hence, the probability that a nucleus undergoes decay after three half-lives is 7/8.

Rectification is the process of conversion of alternating current into direct current. The conversion first powers to alternating current then use a transformer to change the voltage, and finally rectifies power back to direct current.

A magnet can attract another magnet or a magnetic substance like iron. However, a magnet can repel another magnet only. So repulsion is the surer test of magnetism.

Magnetic dipole moment = Pole strength × Magnetic length.

Pole strength = Magnetic dipole moment / Magnetic length

Pole strength = 50.2

Pole strength = 25 Am.