MCQ
Force between the two parallel wires carrying currents has been used to define:
  • Ampere
  • B
    Coulomb
  • C
    Volt
  • D
    Watt

Answer

Correct option: A.
Ampere

Ampere is defined as the constant current that will produce an attractive force of $2 \times 10^{-7}$ newton per metre of length between two straight, parallel conductors $($carrying the constant current$)$ of infinite length and negligible circular cross section placed one metre apart in a vacuum. This is the Ampere's Force Law.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In a step up transformer, 220 V is converted into 200 V. The number of turns in primary coil is 600. What is the number of turns in the secondary coil
Following figures show different combinations of identical bulb$(s)$ connected to identical battery$(ies)$. Which option is correct regarding the total power dissipated in the circuit?
Current through $ABC$ and $A'B'C'$ is $I$. What is the magentic field at $P$ ? $BP = PB' = r$ (Here $C'B'PBC$ are collinear)
The Young's experiment is performed with the lights of blue $4360 \;\mathring A$ and green colour $5460 \;\mathring A$, If the distance of the 4th fringe from the centre is $x$, then
Imagine that the electron in a hydrogen atom is replaced by a muon $(\mu) .$ The mass of muon particle is $207$ times that of an electron and charge is equal to the charge of an electron. The ionization potential of this hydrogen atom will be ............. $eV$
An opera glass (Gallilean telescope) measures $9 \,cm$ from the objective to the eyepiece. The focal length of the objective is $15\, cm$. Its magnifying power is
A straight rod of mass $m$ and length $L$ is suspended from the identical spring as shown in the figure. The spring stretched by a distance of $x_0$ due to the weight of the wire. The circuit has total resistance $R\Omega$ . When the magnetic field perpendicular to the plane of the paper is switched on, springs are observed to extend further by the same distance. The magnetic field strength is 
In heavy fog, yellow colour of headlight of vehicle is prefered as compare to other colours, Why ?
During the nuclear fusion reaction
A heater coil connected to a supply of a $220\, V$ is dissipating some power ${P_1}.$ The coil is cut into half and the two halves are connected in parallel. The heater now dissipates a power ${P_2}.$ The ratio of power ${P_1}\,\,:\,\,{P_2}$ is