The potential difference applied to an X-ray tube is 5 kV and
the current through it is 3.2 mA. Then the number of
electrons striking the target per second is
- $ 2 \times 10^{16} $
- $ 5 \times 10^{6} $
- $ 1 \times 10^{17} $
- $ 4 \times 10^{15} $
The Correct Option is A
Solution and Explanation
Substituting $ i = 3.2 \times 10^{-3} A,
\, \, \, \, \, \, \, \, e = 1.6 \times 10^{-19} C \, \, and \, \, t = 1s $
we get, $ n = 2 \times 10^{16} $
Top Questions on Electric Current
- A current of 2 A flows through a resistor for 10 minutes. What is the total charge that flows through the resistor?
- VITEEE - 2025
- Physics
- Electric Current
- When the switch of the circuit is turned on, the filament of the bulb glows instantaneously because:
- CBSE CLASS XII - 2025
- Physics
- Electric Current
- Why can't the DC ammeter measure an alternating current?
- UPCATET - 2025
- Physics
- Electric Current
- The area of cross-section of a copper wire is $4 \times 10^{-7} m^2$ and the number of electrons per cubic meter in copper is $8 \times 10^{28}$. If the wire carries a current of 6.4 A, then the drift velocity of the electrons (in $10^{-3} m/s$) is
- AP EAPCET - 2025
- Physics
- Electric Current
- In an electric circuit, the device used to prevent damage to the electrical appliances due to overloading is:
- AP POLYCET - 2025
- Physics
- Electric Current
Questions Asked in JEE Advanced exam
- Consider the vectors $$ \vec{x} = \hat{i} + 2\hat{j} + 3\hat{k},\quad \vec{y} = 2\hat{i} + 3\hat{j} + \hat{k},\quad \vec{z} = 3\hat{i} + \hat{j} + 2\hat{k}. $$ For two distinct positive real numbers $ \alpha $ and $ \beta $, define $$ \vec{X} = \alpha \vec{x} + \beta \vec{y} - \vec{z},\quad \vec{Y} = \alpha \vec{y} + \beta \vec{z} - \vec{x},\quad \vec{Z} = \alpha \vec{z} + \beta \vec{x} - \vec{y}. $$ If the vectors $ \vec{X}, \vec{Y}, \vec{Z} $ lie in a plane, then the value of $ \alpha + \beta - 3 $ is ________.
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
- JEE Advanced - 2025
- binomial expansion formula
- The total number of real solutions of the equation $$ \theta = \tan^{-1}(2 \tan \theta) - \frac{1}{2} \sin^{-1} \left( \frac{6 \tan \theta}{9 + \tan^2 \theta} \right) $$ is
(Here, the inverse trigonometric functions $ \sin^{-1} x $ and $ \tan^{-1} x $ assume values in $[-\frac{\pi}{2}, \frac{\pi}{2}]$ and $(-\frac{\pi}{2}, \frac{\pi}{2})$, respectively.)- JEE Advanced - 2025
- Inverse Trigonometric Functions
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is:
- JEE Advanced - 2025
- Dimensional Analysis
- Let $$ \alpha = \frac{1}{\sin 60^\circ \sin 61^\circ} + \frac{1}{\sin 62^\circ \sin 63^\circ} + \cdots + \frac{1}{\sin 118^\circ \sin 119^\circ}. $$ Then the value of $$ \left( \frac{\csc 1^\circ}{\alpha} \right)^2 $$ is \rule{1cm}{0.15mm}.
- JEE Advanced - 2025
- Some Applications of Trigonometry
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.