Basic Engineering Mathematics, Fifth Edition

58 Basic Engineering Mathematics

Hence, 42× 105 = 4. 2 × 106 in engineering

notation

=4.2 Min prefix form.

(b) Enter 47÷ 1010 =

47

10000000000

into the calcu-

lator. Press=

NowpressENGandtheansweris4. 7 × 10 −^9.

From the table of prefixes on page 55, 10−^9

corresponds to nano.

Hence, 47÷ 1010 F=4.7× 10 −^9 Fin engineer-

ing notation

=4.7nFin prefix form.

Problem 8. Rewrite (a) 0.056mA inμA

(b) 16700kHz as MHz

(a) Enter 0. 056 ÷1000 into the calculator (since milli

means÷1000). Press=

Now press ENG and the answer is 56× 10 −^6.

From the table of prefixes on page 55, 10−^6

corresponds to micro.

Hence, 0.056mA=

0. 056

1000

A= 56 × 10 −^6 A

= 56 μA.

(b) Enter 16700×1000 into the calculator (since kilo

means×1000). Press=

Now press ENG and the answer is 16. 7 × 106.

From the table of prefixes on page 55, 10^6 corre-

sponds to mega.

Hence, 16700kHz= 16700 ×1000Hz

= 16. 7 × 106 Hz

=16.7MHz

Problem 9. Rewrite (a) 63× 104 VinkV

(b) 3100pF in nF

(a) Enter 63× 104 into the calculator. Press=

Now press ENG and the answer is 630× 103.

From the table of prefixes on page 55, 10^3 corre-

sponds to kilo.

Hence, 63× 104 V= 630 × 103 V=630kV.

(b) Enter 3100× 10 −^12 into the calculator. Press=

Now press ENG and the answer is 3. 1 × 10 −^9.

From the table of prefixes on page 55, 10−^9

corresponds to nano.

Hence, 3100pF= 31 × 10 −^12 F= 3. 1 × 10 −^9 F

=3.1 nF

Problem 10. Rewrite (a) 14700mm in metres

(b) 276cm in metres (c) 3.375kg in grams

(a) 1m=1000mm, hence

1mm=

1

1000

=

1

103

= 10 −^3 m.

Hence, 14700mm= 14700 × 10 −^3 m= 14 .7m.

(b) 1m=100cm, hence 1cm=

1

100

=

1

102

= 10 −^2 m.

Hence, 276cm= 276 × 10 −^2 m= 2 .76m.

(c) 1kg=1000g= 103 g

Hence, 3.375kg= 3. 375 × 103 g=3375g.

Now try the following Practice Exercise

PracticeExercise 34 Engineering notation

(answers on page 343)

In problems 1 to 12, express in engineering nota-

tion in prefix form.

1. 60000Pa


2. 0.00015W


3. 5× 107 V


4. 
   
   
   
   5. 5 × 10 −^8 F
   
   
   
   


5. 100000W


6. 0.00054A


7. 15× 105 


8. 225× 10 −^4 V


9. 35000000000Hz


10. 
    
    
    
    1. 5 × 10 −^11 F
    
    
    
    


11. 0.000017A


12. 46200