Advertisements
Advertisements
Question
The voltage applied to a given rheostat is made four times its initial value. By what factor will be resistance of the rheostat change?
Advertisements
Solution
The resistance of the rheostat will not change at all as it does not depend on the voltage applied across it.
RELATED QUESTIONS
Find the equivalent resistance between points A and B
When a 4 Ω resistor is connected across the terminals of a 12 V battery, the number of coulombs passing through the resistor per second is:
(a) 0.3
(b) 3
(c) 4
(d) 12
Name the material which is used for making the heating element of an electric iron.
How does the resistance of a pure metal change if its temperature decreases?
How does the presence of impurities in a metal affect its resistance?
Calculate the resistance of an aluminium cable of length 10 km and diameter 2.0 mm if the resistivity of aluminium is 27 × 10−8 Ωm.
What potential difference is needed to drive a current o f 1 A through a 5 Ω resistor?
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
State expression for Resistance connected in parallel.
2Ω resistor A, 1Ω resistor B and 4Ω resistor C are connected in parallel. The combination is connected across a 2V battery of negligible resistance. Draw the diagram of the arrangement and calculate:
(i) The current in each resistor A and C,
(ii) The current through battery.
