Question
The potential difference between the terminals of a 6.0V battery is 7.2V when it is being charged by a current of 2.0A. What is the internal resistance of the battery?
✓
Answer
$\text{V}=\in+\text{ir}$$\Rightarrow7.2=6+2\times\text{r}$
$\Rightarrow1.2=2\text{r}\Rightarrow\text{r}=0.6\Omega.$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
From a capillary tube of insufficient length water does not spread outside, why?
Estimate the time taken by the oscillating pendulum to shift from x = 0 to $\text{x}=\frac{\text{A}}{2}$ where A is the amplitude.
→A rod of length l and mass M held vertically is let go down, without slipping at the point of contact. What is the velocity of the top end at the time of touching the ground? 
If the earth were made of lead of relative density 11.3 , what then would be the value of acceleration due to gravity on the surface of the earth? Radius of the earth $=6.4 \times 10^6 m$ and $G =6.67 \times 10^{-11} Nm ^2 kg^{-2}$.
→Two pendulum of length 1.00 and 1.1025 meters start vibrating simultaneously. After how many oscillations will they start oscillating together again ?
A heavy box is kept on a smooth inclined plane and is pushed up by a force $F$ acting parallel to the plane. Does the work done by the force $F$ as the box goes from $A$ to $B$ depend on how fast the box was moving at $A$ and $B$ ? Does the work by the force of gravity depend on this?
→A wire of length L and radius r is clamped rigidly at one end. When the other end of the wire is pulled by a force f, its length increases by I. Another wire of the same material of length 2L and radius 2r, is pulled by a force 2f. Find the increase in length of this wire.
A heavy mass m is hanging from a string in equilibrium without breaking it. When this same mass is set into oscillation, the string breaks. Explain.
A particle of mass 0.3kg is subjected to a force F = -kx with k = 15N/m. What will be its initial acceleration if it is released from a point x = 20cm?
A body of mass 6kg is floating in a liquid with $\frac23$ of its volume inside the liquid. Find ratio between the density of the body and density of liquid. Take $g = 10m/ s^2$.
→