All types of electromagnetic radiation have different wavelengths and frequencies but travel at the same speed. The frequency for different wavelengths are around:

1. $106 \mathrm{Hz}$ for radio-frequency

2. $1010 \mathrm{Hz}$ for microwave

3. $1013 \mathrm{Hz}$ for infrared

4. $1015 \mathrm{Hz}$ for visible light

Which of the above is used for radar?

Consider the following statements:
$1.$ An atom consists of a positively charged sphere and the electrons are embedded in it.
$2.$ The negative and positive charges are equal in magnitude. So, the atom as a whole is electrically neutral.

Which of the statements given above is/are correct about Thomson's model of an atom?

Which of the following statements with regard to isotopes and isobars is/are correct?
$1.$ Isotopes have the same mass number.
$2.$ Isobars have the same atomic number.

Select the correct answer using the codes given below.

Match the Column I with Column II and select the correct answer using the codes given below: