FREE NEET Physics Questions and Answers
On a lab bench, two tiny lead balls with weights of 5 kg and 10 kg are attached at a distance of 100 cm apart. The distance is now only 20 cm after a pupil transfers the larger mass in the direction of the smaller mass. What influenced the gravitational force between the lead balls when the mass was moved?
The inverse-square law is observed in the gravitational field. The force will increase by a factor of 5(2), or 25 when the distance is reduced by a factor of 5.
What size resistor should be placed across the 12V battery's terminals in order to generate 500mA of current?
"V=IR is the formula for Ohm's law. V is equal to 12V in this case, while I is equal to 0.5A. After calculating the resistance, R, we get: R=V/I Substitute known values with the unknown resistance's value, then find a solution: R=12V/0.5A=24Ω"
As seen in the illustration, let's assume that a magnetic field is arranged so that it is pointing straight to the left. Which way would the trajectory of a positively charged particle curve if it were to start moving through this magnetic field from the right?
"""Understanding the variables that affect the magnetic force that a charge experiences is crucial to finding the answer to this question. The magnetic force equation can be written out first. FB=qvBsin(θ) According to the equation above, the magnetic force is inversely proportional to the particle's charge, its speed, and the magnetic field's overall strength. However, for the sake of this inquiry, the angle of the particle's velocity with respect to the magnetic field is crucial. Keep in mind that if theta equals zero, the sine of theta will also be equal to zero. As a result, the magnetic force will also be zero. The same holds true if theta is set to 180 degrees. Theta is equal to 180o since the particle is travelling in an opposite direction from the magnetic field lines while still moving parallel to them. As a result, the magnetic force acting on the particle is null. While a result, the particle won't alter course as it travels through the magnetic field."""
Two spheres that are in contact but isolated from the ground are approached by a charged rod bearing a negative charge. What kind of charge will be on the two spheres if they are then separated?
The negatively charged rod will cause a flow of charge in the two spheres when it is brought close to one of them, causing the regions farthest from the rod to become most negative and the regions closest to it to become most positive. We refer to this as charge through induction.
You are required to design a circuit that has a total resistance between 40Ω and 45Ω. What resistor configuration should you use to achieve this?
It is easy to "eyeball" this and see that this is at least conceivable by connecting R1 and R2 in parallel to R3 in series. A network with an overall resistance of less than 50 ohms must be created by R1 and R2 working in parallel. The total could range between 40 and 45 when put in series with R3 (10). Although one may perform the calculations to determine the total resistance to confirm, the goal of this question is to rapidly rule out the other incorrect answer options using general principles.
What distinguishes gravitational and electrical forces most significantly?
Because charges can be positive or negative, electric forces can be both attracting and repellent. Because mass is always positive, gravitational forces are limited to attractive forces.
How can a positively charged rod make a conducting sphere on an insulating surface negatively charged?
When a charged object is brought close to a neutral object, charge by induction occurs. The neutral object will become polarized as a result of the charged object's charges shifting the free charges in the neutral object. A neutral object will acquire a negative charge when the charged object is positive.
A rope is fastened to a 50 kilogram cinder block that is lying on the ground. What is the lowest tension the rope can withstand before snapping if it is pulled so that the block accelerates directly upwards at a velocity of 5(m/s2)?
"""In this situation, the rope must be strong enough to withstand both gravity and the force necessary to accelerate the block. F=ma provides both: Fgravity=(50kg)(9.81ms2)=490.5N Faccelerate=(50kg)(5ms2)=250N\sFtotal=490.5N+250N=740.5N"""
An electric field that is vertically upward and oriented along the +y axis interacts with a charged particle moving along the +x axis. What is the sign of the charge on this particle if the force from the field is downward for the charged particle?
An electric force that is directed in the same direction as the electric field will be felt by positive charges when they are in one. The force will be directed in the opposite direction from the electric field if the charge is negative. The charge must have a negative sign because the charged particle experiences a force that opposes the electric field.
A vertically downward electric field, or along the negative y-axis, is encountered by an electron moving along the +x-axis. After the electron enters the electric field, in what direction will the electric force be acting on it?
An electric force that is directed in the same direction as the electric field will be felt by positive charges when they are in one. The force will be directed in the opposite direction from the electric field if the charge is negative. Since the electron is travelling in an electric field that is oriented in the negative y-direction, it will experience an upward force that is oriented in the positive y-direction.
What is the peak-to-peak AC current of 100V's RMS voltage?
"We are told that the current is 100V peak-to-peak, so the peak voltage is half of this, or 50V. By definition, to convert peak voltage to RMS voltage, we must divide the peak voltage by 2: ""This question requires two steps: the first is to calculate the peak voltage of the AC current, and the second requires conversion of the peak voltage to an RMS voltage. 50V/2–√=35.5V"""
A rope is fastened to a 50 kilogram cinder block that is resting on a frictionless surface. What is the least amount of stress the rope can withstand before snapping if it is pulled parallel to the ground so that the block accelerates at a rate of 5(m/s2)?
It is an easy example of F=ma. Here, m is equal to 50 kg, and an is equal to 5 m/s2. If we substitute, we get F=250N.
What should the resistance of the heating element be if the battery is set to 24V and the total radiated power is 60W?
To determine the power lost through a resistor that is wired to a battery is what is being requested of us. P=V2/R is a known equation. 60W=(24V)2/R is obtained by substituting the above values. 9.6Ω is the result of the R equation.
When electrostatic circumstances are present, a conductor is positioned in an electric field. Which of the following claims applies to this circumstance?
A thing that can move charges freely is referred to as a conductor. In particular, valence electrons, which are the most mobile and outermost electrons in each atom, migrate across the conductor until its internal electric field is zero. Until this criterion is met, these electrons will move. Any electric field at the surface must be perpendicular to that surface due to the presence of charged particles there and the fact that they are no longer moving.
The identical positive charge +Q is enclosed by Gaussian surfaces A and B. Gaussian surface A has a surface area that is three times more than Gaussian surface B. Electric field flux via Gaussian surface A is equal to .
Gauss' law states that the net total electric charge inside a Gaussian surface equals the total electric flow. The electric flux will remain constant even if the Gaussian surface is three times larger if the total electric charge is the same on both surfaces.
The electrical forces between two interacting charges is __________ when their magnitudes are multiplied by two.
According to Coloumb's law, the electrical force between two charges will grow as their respective charges interact more strongly. In particular, doubling the magnitude of the two interacting charges will cause an quadruple rise in the electrical force.