Electric Field and Electric Field Lines

Correct answer: A. Closer to the smaller charge

Explanation: The governing concept is superposition of electric fields. For two positive charges, the fields between them point in opposite directions, so cancellation is possible there. If the charges are q and Q with Q greater than q, equality requires kq/x² = kQ/(d−x)². The point must be nearer q, because being closer increases the smaller charge's field until it balances the larger charge's field. Thus A is correct; the midpoint works only for equal charges.

Correct answer: A. To the right

Explanation: Step 1: Moving slightly right makes the point closer to the right positive charge and farther from the left one. Step 2: The right charge repels the positive test charge leftward more strongly than the left charge repels it rightward. Step 3: Therefore the initial force is toward the left, so option A would be wrong if chosen.

Correct answer: A. Twelve times

Explanation: Step 1: Electric field due to a point charge is directly proportional to charge and inversely proportional to the square of distance. Step 2: Tripling the charge makes the field three times and halving the distance makes it four times. Step 3: Combining both effects gives twelve times so handle both changes separately.

Correct answer: A. Toward the left

Explanation: Step 1: At the midpoint the fields due to equal positive charges are equal and opposite. Step 2: Moving slightly right makes the point closer to the right charge so its leftward field becomes stronger. Step 3: Symmetry applies only at the exact midpoint so compare distances nearby.

Correct answer: A. Toward the right

Explanation: Step 1: The field due to a negative charge points toward the charge. Step 2: Moving left from the midpoint makes the left charge closer so its leftward field is stronger than the rightward field. Step 3: The net field is toward the closer negative charge.

Correct answer: A. Because fields add between them and balance is possible outside near the smaller charge

Explanation: Step 1: Between opposite charges the fields point in the same direction so they do not cancel. Step 2: Outside the pair the directions can be opposite and near the smaller charge its field can balance the distant larger charge field. Step 3: For unequal opposite charges look outside for the zero point.

Correct answer: A. Because the distance must be smaller to make the smaller charge field equal

Explanation: Step 1: The field of a point charge increases with charge magnitude and decreases with square of distance. Step 2: The smaller charge can balance the larger charge only when the point is closer to it. Step 3: For zero-field points, first check direction and then distance balance.

Correct answer: A. Outside on the side of the smaller positive charge

Explanation: Step 1: Between opposite charges, the two fields point in the same direction, so cancellation is not possible there. Step 2: Outside the charges, the fields can be opposite. Step 3: The balance point lies outside on the side of the smaller charge because the larger charge must be farther away.