Basic Electrical Theory
METRIC SYSTEM AND POWERS OF TEN
To convert a number expressed as a negative power of 10 to a decimal number,
move the decimal point to the left as many places as the value of the exponent.
To convert 5 x 10-3A, move the decimal point 3 places to the left
(0.005), then drop the multiple of the power of 10, obtaining
5 x 10-3A = 0.005A
To multiply 2 or more numbers expressed as powers of 10, multiply the
coefficients to obtain the new coefficient, and add the exponents to obtain the new
exponent of 10.
To multiply 2 x 105 by 3 x 10-3, multiply 2 x 3 to get 6, then add
the exponents of the powers of 10, 5 + (-3), to get an exponent of
2, obtaining a product of 6 x 102.
(2 x 105) (3 x 10-3) = 6 x 102
To divide powers of 10, use the formula:
1 x 10n
We can transfer any power of 10 from numerator to denominator, or vice-versa,
simply by changing the sign of the exponent.
To divide 8 x 10-5 by 2 x 10-4, divide the numerical number 8 by
2 = 4, then bring the power of 10, in the denominator, up to the
numerator and change the sign of its exponent, then add the