Question : Decibel is the unit used for:

Option 1: speed of light

Option 2: intensity of heat

Option 3: intensity of sound

Option 4: radio wave frequency

Question : The SI unit of power of the lens is ________.

Option 1: candela

Option 2: mole

Option 3: watt

Option 4: dioptre

Question : The important unit of a microprocessor is:

Option 1: ALU

Option 2: array of registers

Option 3: control unit

Option 4: All of the above

Question : The unit digit in the product $7^{71}\times 6^{59}\times 3^{65}$ is:

Option 1: $1$

Option 2: $2$

Option 3: $3$

Option 4: $4$

Question : The density of the population is expressed as:

Option 1: number of rural persons per unit area.

Option 2: number of literate persons per unit area.

Option 3: number of persons per unit area.

Option 4: number of animals and persons per unit area.