The length of wire PQ in case of A is equal to the diameter of the semicircle formed by the wire CDE ">

Look at figure.

The length of wire PQ in case of A is equal to the diameter of the semicircle formed by the wire CDE

Academic Physics NCERT Class 7

The length of the wire in $(A)$ is shorter than the wire in $(B)$. So, heat will reach to pin in $(A)$ fast and the wax will melt. So, pin in $(A)$ will fall first.

Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

44 Views

A piece of wire 144 cm long is bent to form a semicircle. Find the diameter of the semicircle in metres.
The diameter of a sphere is $6\ cm$. It is melted and drawn into a wire of diameter $0.2\ cm$. Find the length of the wire.
If the length of a wire is doubled by taking more of the wire, What happens to its resistance?
$2.2$ cubic dm of brass is to be drawn into a cylindrical wire $0.25\ cm$ in diameter. Find the length of the wire.
The diameter of a metallic sphere is equal to \( 9 \mathrm{~cm} \). It is melted and drawn into a long wire of diameter \( 2 \mathrm{~mm} \) having uniform cross-section. Find the length of the wire.
Angle subtended by the diameter of a semicircle is _______.
The diameter of a copper sphere is $18\ cm$. The sphere is melted and is drawn into a long wire of uniform circular cross-section. If the length of the wire is $108\ m$, find its diameter.
A copper rod of diameter \( 1 \mathrm{~cm} \) and length \( 8 \mathrm{~cm} \) is drawn into a wire of length \( 18 \mathrm{~m} \) of uniform thickness. Find the thickness of the wire.
A given length of a wire is doubled of itself and this process is repeated once again. By what factor does the resistance of the wire changes?
What is the usual colour of the insulation of (a) live wire(b) neutral wire, and (c) earth wire?
A $6\Omega$ resistance wire is double up by folding. Calculate the new resistance of the wire.
A wire is bent to form a square of side 15cm. Ir the wire is reshaped to form a rectangle of length 20cm, find the perimeter of the rectangle and breadth of the rectangle
A thick wire is hanging from a wooden table. An anticlockwise magnetic field is to be produced around the wire by passing current through this wire by using a battery. Which terminal of the battery should be connected to the:(a) top end of wire? (b) bottom end of wire? Give reason for your choice.
An electric pole is \( 10 \mathrm{~m} \) high. A steel wire tied to top of the pole is affixed at a point on the ground to keep the pole up right. If the wire makes an angle of \( 45^{\circ} \) with the horizontal through the foot of the pole, find the length of the wire.
A copper wire has diameter 0.5 mm and resistivity of $1.6\times10^{-8}$â„¦ m. What will be the length of this wire to make its resistance $10\ â„¦$? How much does the resistance change if the diameter is doubled?

Kickstart Your Career

Get certified by completing the course

Get Started

Advertisements