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Answers
Answer:
Explanation:
1 a . Approximately less than one ohm
b. Approximately less than 1 ohm
2 .
R1 = 100Ω
R2 = 50 Ω
R3 = 500 Ω
1/Rp = 1/100 + 1/50+ 1/500
5/500 + 10/500 + 1/500 [ after taking LCM = 500 ]
therefore - 1/Rp = 4/125
Rp = 31.25 Ω
resistance of electric iron : 31.25 Ω
I = V/Rp
= 220 * 100 /31.25 * 100
= 7.04 A
3.
Advantages of parallel connections are :
* it provides same potential difference for all appliances in it .
* parallel connections provides different amount of current for different electric appliances for working .
* if one of the devices in parallel connection does not work other device will keep on working .
4. R1 = 2 Ω
R2 = 2Ω
R3 = 6Ω
a] 4 Ω
Connect two resistors in parallel and one in series .
therefore we get ,
1/Rp = 1/3+1/6 =3/6 [ after LCM = 6]
1/Rp = 1/2
Rp = 2 Ω
there fore Rs = 2Ω + 2Ω
= 4 Ω
b] 1/Rp = 1/2 + 1/ 3 + 1/6
LCM = 6
therefore Rp = 1 Ω
5 .
R1 = 4 Ω
R2 =8Ω
R3=12Ω
R4=24Ω
a to get max resistance , resistors must be connected in series ,
therefore Rs = 48 Ω
b . to get the lowest resistance we must connect the resistors in parallel ,
1/Rp = 1/4 + 1 /8 + 1/12 +1/24
= 6 + 3 +2+1/ 24
= 1/2
therefore Rp = 2 Ω