EASY
JEE Main/Advance
IMPORTANT
Earn 100

If a copper wire is stretched to make its radius decrease by 0.1%, the percentage change in its resistance is approximately.

50% studentsanswered this correctly

Important Questions on Current Electricity

MEDIUM
JEE Main/Advance
IMPORTANT
The potential difference between the terminals of a battery of emf 10 V and internal resistance 1 Ω drops to 9.8 V when connected across an external resistance. The resistance of the external resistor is
EASY
JEE Main/Advance
IMPORTANT
The two ends of a uniform conductor are joined to a cell of emf ε and some internal resistance. Starting from the midpoint P of the conductor, we move in the direction of the current and return to P. The potential V at every point on the path is plotted against the distance covered (x). Which of the following is correctly represents this.
EASY
JEE Main/Advance
IMPORTANT

A cell of emf E having an internal resistance r is connected to an external resistance R. The potential difference V across the resistance R varies with R as shown in figure by the curve :

Question Image

EASY
JEE Main/Advance
IMPORTANT

In a circuit shown in figure resistances R1 and R2 are known, as well as emf’s E1 and E2. The internal resistances of the sources are negligible. At what value of the resistance R will the thermal power generated in it be the highest ?

Question Image

 

MEDIUM
JEE Main/Advance
IMPORTANT
A resistor R is connected to a parallel combination of two identical batteries each with emf E and an internal resistance r. The potential drop across the resistance R is-
HARD
JEE Main/Advance
IMPORTANT

The equivalent resistance between A and B will be (in Ω)

Question Image

MEDIUM
JEE Main/Advance
IMPORTANT

A wire is in the form of a tetrahedron. The resistance of each edge is r. The equivalent resistances between corners 12 and 13 are respectively-

Question Image

MEDIUM
JEE Main/Advance
IMPORTANT

The equivalent resistance between points A and B is: 

Question Image