Answer:
3. more resistance and draws more current
Explanation:
According to a derivation from Ohm's law, the power, P, generated by the bulb is directly proportional to square of the current, I, passing through it. i.e
P ∝ I²
P = I²R -------------------- (i)
Where;
R = constant of proportionality called resistance
From equation (i), it can thus be deduced that the power, P, is also directly proportional to the resistance, R.
Thus;
(i) When power increases, resistance increases
(ii) When power increases, current also increases.
So for the 100-watt bulb, compared to the 60-watt bulb, there will be more resistance and more current will be drawn.
Answer:
Option 1. Less resistance and draws more current
Explanation:
To better understand this concept, let us determine the resistance and current of each bulb assuming a 240V supply.
Recall:
Power = current (I) x voltage (V)
P = IV
Power = square voltage/ resistance
P = V^2 /R
For the 60watt bulb:
Power (P) = 60watts
Voltage = 240V
Current (I) =?
Resistance =?
A. P= IV
60 = I x 240
Divide both side by 240
I = 60/240
I = 0.25A
B. P = V^2 /R
60 = (240)^2 / R
Cross multiply to express in linear form
60 x R = (240)^2
Divide both side by 60
R = (240)^2 / 60
R = 960 ohms
For 100watts bulb:
Power (P) = 100watts
Voltage = 240V
Current (I) =?
Resistance =?
A. P= IV
100 = I x 240
Divide both side by 240
I = 100/240
I = 0.42A
B. P = V^2 /R
100 = (240)^2 / R
Cross multiply to express in linear form
100 x R = (240)^2
Divide both side by 100
R = (240)^2 / 100
R = 576 ohms
Summary:
60watts bulb has a current of 0.25A and a resistance of 960 ohms
100watts bulb has a current of 0.42A and a resistance of 576 ohms.
Comparing the resistance and current of the 60watts and 100watts bulb under the same supply of 240V,
the 100watts bulb has lesser resistance than the 60watts bulb and draws more current than the 60watts bulb.
