Contact forces and non-contact forces - class-VIII
Description: contact forces and non-contact forces | |
Number of Questions: 40 | |
Created by: Jatin Goyal | |
Tags: newton's laws of motion motion, force and speed primary concept of force and energy physics dynamics - explaining motion force and newton's laws mechanics motion, force and pressure force magnetic fields and electromagnetism force and pressure |
Consider two conducting plates $A$ and $B$, between which the potential difference is $5 V$, plate $A$ being at a higher potential. A proton and an electron are released at plates $A$ and $B$ respectively. The two particles then move towards the opposite plates - the proton to plate $B$ and the electron to plate $A$. Which one will have a larger velocity when they reach their respective destination plates?
$F _g$ and $F _e$ represent gravitational and electrostatic force respectively between electrons situated at a distance $0.1\,m. F _g/F _e$ is of the order
Four point charge of $+10^{-7}C, -10^{-7}C, -2\times 10^{-7}C$ and $+2\times 10^{-7}C$ are placed respectively at the corners $A, B, C, D$ of a $0.05\ m$ square. Find the magnitude of the resultant force on the charge at $D$.
An $\alpha$-particle is the nucleus of a helium atom. It has a mass $m=6.64 \times 10^{-27}$kg and a charge $q = + 2e = 3.2 \times 10^{-19}$ C. Compare the force of the electric repulsion between two a-particles with the force of gravitational attraction between them.
Electrostatic force and gravitational force differ in which respect?
The ratio of electric force between two electrons to the gravitational force between them is of the order
During winter, clothes tend to stick to our body as an action of ______ force.
When an object is rubbed with some materials, it acquires charges and becomes ________ object.
Gravitational force is a/an ______ force.
Under action of which force does water flow from an open tap towards ground?
Does moon have its own gravity?
Which of the following is the weakest force?
There are circumstances in which two objects exert forces on one another even though they are not touching. Such forces are called (Mark the most appropriate answer)
It is easier to drive a screw rather than a nail of the same size into a wall because:
Which of the following is a non contact force?
Let E,G and N represents the magnitude of electromagnetic, gravitational and nuclear forces between protons and electrons at a given separation (1 fermi meter). Then
Gravitational force acts
The force of gravity is a ______ force
When a force is exerted on an object without any contact, the force is known as ____
Which of the following is NOT a non-contact force?
Unlike poles of two magnets ______ each other.
Like poles of two magnets _____ each other.
When a ball is hit by a bat, forces acting on the ball are
Gravity is shown by
Attraction or repulsion between two objects can also be seen us another form of ____
The force exerted by a charged body on another charged or uncharged body is known as ______ force.
Gravitational force is a _____ force.
Attraction and repulsion between charged objects are examples of _______ force.
When you ride a cycle, force(s) acting on the cycle is/are
Objects fall towards the earth because the earth pulls those. This pull is called _________ force.
Electrostatic force is also a ____ force.
Which of the following is not a contact force?
Magnetic force is a non contact force because for magnetic force to apply
Which of the following is a non-contact force?
Fruits detached from a tree fall down due to force of gravity. We know that a force arises due to interaction between two objects. Name the objects interacting in this case.
State whether true or false:
Which one of the following forces is a contact force?