Physics MCQs for NEET — Practice Questions with Answers

To find the ratio of 10 microns to 1 nanometer, you need to convert both units to meters first. 1 micron (µm) is $10^{-6}$ meters, and 1 nanometer (nm) is $10^{-9}$ meters. Therefore, the ratio is $ \frac{10 imes 10^{-6}}{10^{-9}} = 10^4 $. Hence, the correct option is $10^4$.

$ { 10 ^ {-15 } \over 100 \times 10 ^ {-9} } = 10 ^ {-8} $

The value of the gravitational constant (G) in the MKS system is $6.67 imes 10^{-11} ext{Nm}^2/ ext{kg}^2$. To convert this to CGS units, we need to convert meters to centimeters and kilograms to grams. 1 meter = 100 cm and 1 kilogram = 1000 grams. Therefore, $G$ in CGS units is $6.67 imes 10^{-11} imes (100^3)/(1000^2) = 6.67 imes 10^{-8} ext{dyn-cm}^2/ ext{gm}^2$. Hence, the correct option is $6.67 imes 10^{-8}$.

1 MeV (Mega electron Volt) is equal to $10^6$ electron Volts. Therefore, 1 MeV = $10^6$ eV.

Length, time and velocity cannot enter in to the list of fundamental quantities because velocity can be expressed in terms of length and time.

1 radian is equal to the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle. To convert radians to degrees, we use the formula: $1 ext{ rad} = rac{180}{ ext{Ï€}} ^ ext{circ}$.

$ 1 amu = 1.66 \times 10 ^ {-27 } kg $ $ = 1.66 \times 10 ^ {-24} gm $ $ 1 gm = 6.023 \times 10 ^ {23} amu $

Power is defined as the rate at which work is done or energy is transferred. The units of power are watt (W), which is equivalent to joule/second (J/s). Other valid units of power include $( ext{ampere})^2 imes ext{ohm}$ and $ ext{ampere} imes ext{volt}$. However, ampere/volt does not represent a unit of power.