State the ways by which the frequency of transverse vibrations of a stretch string can be increased?
The V-I graph for a series combination and for a parallel combination of two resistors is shown in the figure below. Which of the two A or B, represents the parallel combination? Give reasons for your answer.
The music system draws a current of 400 mA when connected to a 12 V
battery.
(i) What is the resistance of the music system?
(ii) The music system if left playing for several hours and finally the battery voltage drops to 320 mA and the music system stops playing when the current.
Calculate the quantity of heat produced in a 20 ohm resistor carrying 2.5 A current in 5 minutes.
State the characteristics required of good thermion emitter.
Characteristics of a good thermion emitter are:
1. The work function of the substances should be low so that the electrons are emitted from it even when it is not heated to a very high temperature.
2. The melting point of the substance should be quite high so that it may melt when it is heated to the temperature required for thermionic emission.
An element decays to after emitting 2 particles and 1 particle. Find the atomic number and atomic mass of the element S.
A radioactive substance is oxidized. Will there be any change in the nature of its radioactivity? Give a reason for your answer?
State the characteristics required in a material to be used as an effective fuse wire.