Physics 1 Marks Question

The terminal pd across a battery is equal to its emf when battery is in open circuit, i.e., when no current is being drawn from the cell.

Because potentiometer doesn't draw any current for itself from the primary circuit and hence gives more accurate measurement thereby acting as an ideal voltmeter. It uses null method to measure.

Only charge goes from the wire, rate of flow of charge is known as current.

Yes, electric field exists within the conductor because it is the electric field which imparts acceleration to electrons for the flow of current.

Current is a scalar quantity because it does not obey the laws of vector addition.

No, the resistance remains same, because length and cross-sectional area of the wire remain unchanged.

As electron doesn't travel linearly so we need to calculate average time thus we need to consider drift distance for long time. That can not be calculated in case of t → 0.

Yes, polarity of electrolytic cell is fixed.

At higher value of current, sufficient heat is produced which raises the temperature of resistor and so causes increase in resistance.