Physics
(a) What are background radiations?
(b) Write an equation of an α-emission from 23892U
(c) What will be the change in the rate of radioactivity if the temperature of the radioactive substance is raised to four times the initial temperature?
Related Questions
(a) Which contains more heat, 1 kg water at 100°C or 1 kg steam at 100°C?
(b) Name a substance that contracts on melting and expands on solidification.
(c) In cold countries, juice bottles are placed underwater, so as to avoid freezing. Why?
Three resistors are joined together as shown in the figure. The resistors are connected to an ammeter and to a cell of emf 9.0 V
Calculate
(a) the effective resistance of the circuit.
(b) the current drawn from the cell.
(a) Name the new and old colour codes of the wire which is connected to the switch of an appliance.
(b) Draw the diagrams of a dual control switch when the appliance is switched ON and OFF.
(c) Calculate the electrical energy consumed when a bulb of 40 W is used for 12.5 h everyday for 30 days.
A boy tunes a radio channel to a radio station 93.5 MHz.
(a) Name and define the scientific wave phenomenon involved in tuning the radio channel.
(b) Now what is the frequency of the channel? Convert this frequency into SI unit.