The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4Ω, what is the maximum current that can be drawn from the battery?
The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4Ω, what is the maximum current that can be drawn from the battery?
Solution and Explanation
Emf of the battery, E = 12 V
Internal resistance of the battery, r = 0.4 Ω
Maximum current drawn from the battery = I
According to Ohm’s law,
\(E = Ir\)
\(I = \frac{E}{r}\)
\(I = \frac{12}{0.4}\)
I = 30 A
The maximum current drawn from the given battery is 30 A
Top Questions on Current electricity
- Two cells of emf 10 V each, two resistors of 20 \( \Omega \) and 10 \( \Omega \), and a bulb B of 10 \( \Omega \) resistance are connected together as shown in the figure. Find the current that flows through the bulb.
- CBSE CLASS XII - 2025
- Physics
- Current electricity
- The equivalent resistance between points A and B in a circuit with two resistors of 6 \(\Omega\) each connected in parallel is:
- BITSAT - 2025
- Physics
- Current electricity
- Two resistors, 4 $\Omega$ and 6 $\Omega$, are connected in parallel to a 12 V battery. What is the total current drawn from the battery?
- BITSAT - 2025
- Physics
- Current electricity
- A current of 3 A flows through a resistor of resistance 4 Ω for 2 minutes. The heat produced is:
- BITSAT - 2025
- Physics
- Current electricity
- Three resistors of $ 2\, \Omega $, $ 3\, \Omega $, and $ 6\, \Omega $ are connected in parallel. What is the equivalent resistance of the combination?
- BITSAT - 2025
- Physics
- Current electricity
Questions Asked in CBSE CLASS XII exam
A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:(i)} Express the distance \( y \) between the wall and foot of the ladder in terms of \( h \) and height \( x \) on the wall at a certain instant. Also, write an expression in terms of \( h \) and \( x \) for the area \( A \) of the right triangle, as seen from the side by an observer.
- CBSE CLASS XII - 2025
- Application of derivatives
- A charge \( -6 \mu C \) is placed at the center B of a semicircle of radius 5 cm, as shown in the figure. An equal and opposite charge is placed at point D at a distance of 10 cm from B. A charge \( +5 \mu C \) is moved from point ‘C’ to point ‘A’ along the circumference. Calculate the work done on the charge.
- CBSE CLASS XII - 2025
- Electrostatics
- Charlie’s desperate attempt to find the third level reflects his frustration with the modern world. Substantiate the above statement with evidence from the story. (The Third Level)
निम्नलिखित गद्यांश की सप्रसंग व्याख्या कीजिए :
‘‘पुर्ज़े खोलकर फिर ठीक करना उतना कठिन काम नहीं है, लोग सीखते भी हैं, सिखाते भी हैं, अनाड़ी के हाथ में चाहे घड़ी मत दो पर जो घड़ीसाज़ी का इम्तहान पास कर आया है उसे तो देखने दो । साथ ही यह भी समझा दो कि आपको स्वयं घड़ी देखना, साफ़ करना और सुधारना आता है कि नहीं । हमें तो धोखा होता है कि परदादा की घड़ी जेब में डाले फिरते हो, वह बंद हो गई है, तुम्हें न चाबी देना आता है न पुर्ज़े सुधारना तो भी दूसरों को हाथ नहीं लगाने देते इत्यादि ।’’
- CBSE CLASS XII - 2025
- सप्रसंग व्याख्या
- Draw the structure of the major monohalo product for each of the following reactions:
- CBSE CLASS XII - 2025
- Haloalkanes And Haloarenes
Concepts Used:
Electric Current
Defining Electric Current
It is the rate of flow of electrons in a conductor. SI Unit - Ampere (A).
Electrons are negatively charged particles hence when they move a number of charges moves.
Note:- The ability of a particular substance to conduct electricity depends on the number of electrons that are able to move . Some of the materials allow current to flow better than others.
What is an Electromotive Force?
If a force acts on electrons to make them move in a particular direction, then up to some extent random motion of the electrons will be eliminated. An overall movement in one direction. The force which acts on the electrons to move them in a certain direction is known as electromotive force and its quantity is known as voltage and is measured in V.