Q. Which statement is true? (i) Kirchoff’s law is equally applicable to both AC and DC. (ii) Semiconductors have a positive temperature coefficient of resistance. (iii) Meter bridge is greater sensitive when the resistance of all four arms of the bridge is of the same order. (iv) The emf of a cell depends upon the size and area of electrodes.
A) (i) and (iv)
B) (ii) and (iv)
C) (iii) and (iv)
D) None of these
Explanation
(c) In a potentiometer there is no current drawn from the cell whose emf is to be measured whereas a voltmeter always draws some current from the cell. Hence, the emf of a cell can be measured accurately using a potentiometer.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.