Published by:
CGP EDU Academic Team
Published on: September 12, 2026
A current is made of two components: a 5 amp D.C. component and a 60 cycle A.C. sinusoidal component of peak value 4 amp. Write down an expression for the resultant current and calculate the average current over a complete cycle and effective value of the current.
Text Solution
Verified by ExpertsThe correct answer is:
C
Step 1: Define the components of the current.
The total current consists of a 5 A D.C. component and a 60 Hz A.C. sinusoidal component with a peak value of 4 A.
Step 2: Write the expression for the A.C. component.
The sinusoidal A.C. component can be expressed as:
$$ I_{AC}(t) = I_{peak} imes ext{sin}(2 heta) = 4 imes ext{sin}(2 heta) $$
Step 3: Combine A.C. and D.C. components.
The total current is:
$$ I(t) = I_{DC} + I_{AC}(t) $$
Thus,
$$ I(t) = 5 + 4 imes ext{sin}(2 heta) $$
Step 4: Calculate average current over one cycle.
The average value of A.C. over one complete cycle is zero, therefore the average current is simply the D.C. component:
$$ I_{avg} = 5 ext{ A} $$
Step 5: Calculate effective (RMS) value of the current.
The RMS value of the A.C. component can be calculated as
$$ I_{rms(AC)} = \frac{I_{peak}}{\sqrt{2}} = \frac{4}{\sqrt{2}} = 2 \sqrt{2} ext{ A} $$
The effective value of the total current is given by:
$$ I_{rms(total)} = \sqrt{I_{DC}^2 + I_{rms(AC)}^2} $$
Thus,
$$ I_{rms(total)} = \sqrt{5^2 + (2 \sqrt{2})^2} = \sqrt{25 + 8} = \sqrt{33} ext{ A} $$
Final Results:
Average current is 5 A and effective current is \sqrt{33} A.
Therefore, the effective value of the total current is approximately 5.74 A.
The total current consists of a 5 A D.C. component and a 60 Hz A.C. sinusoidal component with a peak value of 4 A.
Step 2: Write the expression for the A.C. component.
The sinusoidal A.C. component can be expressed as:
$$ I_{AC}(t) = I_{peak} imes ext{sin}(2 heta) = 4 imes ext{sin}(2 heta) $$
Step 3: Combine A.C. and D.C. components.
The total current is:
$$ I(t) = I_{DC} + I_{AC}(t) $$
Thus,
$$ I(t) = 5 + 4 imes ext{sin}(2 heta) $$
Step 4: Calculate average current over one cycle.
The average value of A.C. over one complete cycle is zero, therefore the average current is simply the D.C. component:
$$ I_{avg} = 5 ext{ A} $$
Step 5: Calculate effective (RMS) value of the current.
The RMS value of the A.C. component can be calculated as
$$ I_{rms(AC)} = \frac{I_{peak}}{\sqrt{2}} = \frac{4}{\sqrt{2}} = 2 \sqrt{2} ext{ A} $$
The effective value of the total current is given by:
$$ I_{rms(total)} = \sqrt{I_{DC}^2 + I_{rms(AC)}^2} $$
Thus,
$$ I_{rms(total)} = \sqrt{5^2 + (2 \sqrt{2})^2} = \sqrt{25 + 8} = \sqrt{33} ext{ A} $$
Final Results:
Average current is 5 A and effective current is \sqrt{33} A.
Therefore, the effective value of the total current is approximately 5.74 A.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
The power is transmitted from a power house on high voltage ac because
The potential difference V and the current i flowing through an instrument in an ac circuit of freq…
In an ac circuit, V and I are given by volts, . The power dissipated in circuit is
Alternating current cannot be measured by dc ammeter because
In an ac circuit, peak value of voltage is 423 volts. Its effective voltage is
In an ac circuit . The time required for the current to achieve its peak value will be