1. Two electric fields of magnitudes 3 N/C and 4 N/C act in the same direction at a point. What is the resultant electric field?
A.
1 N/C
B.
7 N/C
C.
12 N/C
D.
4 N/C
Correct Answer:
7 N/C
Explanation:
Electric fields are vectors, so fields acting in the same direction are added: 3 N/C + 4 N/C = 7 N/C.
2. Two electric fields of magnitudes 8 N/C and 3 N/C act in opposite directions at a point. What is the magnitude of the resultant field?
A.
11 N/C
B.
24 N/C
C.
5 N/C
D.
3 N/C
Correct Answer:
5 N/C
Explanation:
For opposite directions, the resultant magnitude is the difference of the two fields: 8 N/C - 3 N/C = 5 N/C.
3. Two perpendicular electric fields have magnitudes 3 N/C and 4 N/C. What is the magnitude of their resultant field?
A.
1 N/C
B.
5 N/C
C.
7 N/C
D.
12 N/C
Correct Answer:
5 N/C
Explanation:
For perpendicular vectors, the resultant magnitude is found using the Pythagorean theorem: √(3² + 4²) N/C = 5 N/C.
4. An electric field of 6 N/C acts eastward and another field of 8 N/C acts northward. In which direction does the resultant field point?
A.
Eastward
B.
Westward
C.
Northward
D.
Northeastward
Correct Answer:
Northeastward
Explanation:
The resultant of an eastward vector and a northward vector points between them, toward the northeast.
5. If two equal electric fields act at a point in exactly opposite directions, what is the resultant electric field?
A.
Twice either field
B.
Equal to either field
C.
Zero
D.
Half of either field
Correct Answer:
Zero
Explanation:
Equal vectors in opposite directions cancel each other, so their vector sum is zero.
6. Electric field E1 is 5 N/C eastward and electric field E2 is 2 N/C westward. What is the resultant electric field?
A.
7 N/C eastward
B.
3 N/C eastward
C.
3 N/C westward
D.
10 N/C eastward
Correct Answer:
3 N/C eastward
Explanation:
The fields are opposite in direction, so their magnitudes are subtracted. The larger field is eastward, giving 5 - 2 = 3 N/C eastward.
7. At a point, three electric fields act in the same direction with magnitudes 2 N/C, 3 N/C, and 5 N/C. What is the resultant field?
A.
4 N/C
B.
5 N/C
C.
10 N/C
D.
30 N/C
Correct Answer:
10 N/C
Explanation:
Since all three fields act in the same direction, their magnitudes are added: 2 + 3 + 5 = 10 N/C.
8. Two electric fields of 10 N/C and 6 N/C act along the same straight line in opposite directions. What is the magnitude of their resultant field?
A.
4 N/C
B.
16 N/C
C.
60 N/C
D.
6 N/C
Correct Answer:
4 N/C
Explanation:
Oppositely directed fields are subtracted, so the resultant magnitude is 10 N/C - 6 N/C = 4 N/C.
9. An electric field has components 4 N/C eastward and 3 N/C northward. What is the magnitude of the resultant electric field?
A.
1 N/C
B.
5 N/C
C.
7 N/C
D.
12 N/C
Correct Answer:
5 N/C
Explanation:
The components are perpendicular, so the resultant magnitude is √(4² + 3²) N/C = 5 N/C.
10. According to the superposition principle, the net electric field at a point due to several charges is obtained by:
A.
Adding the electric field vectors due to each charge
B.
Adding only the magnitudes of the charges
C.
Multiplying all individual electric fields
D.
Using only the field due to the nearest charge
Correct Answer:
Adding the electric field vectors due to each charge
Explanation:
The superposition principle states that the net electric field is the vector sum of the fields produced independently by all the charges.
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