0
What else can I help you with?
Can the potential difference across a battery be greater than its EMF?
If the emf of a battery is E Volt, the potential difference across a battery is given byV = E -I r where I is the current in the circuit and r is the inetrnal resistance.Hence E and V will be equal only when I = 0.The maximum potential difference across the battery will be equal to E only if I = 0.In gnereral potential difference can be equal or less than the emf.E.m.f can never exceed the potential difference.=====================================A battery charger is a device used to put energy into a secondary cell or (rechargeable) batteryby forcing an electric current through it.Hence to charge a battery another source of emf is needed.The combined emf is now will be (E - E1) where E is the emf of the battey in quesiton and E 1 is the emf of the external source used to charge the battery.Note that E-E1 will be negative in sign.======================================...A battery is charged only when its emf is less than its maximum emf.Suppose that the maximum emf of a cell is 1.5V. The battery should be charged only when its emf is less than 1.5 V say 0.5 V.To charge the cell we use a different source of emf E1 say 3V.The positive of the second source is connected to the negative of the cell so that theCombined emf is now 0.5 - 3 = -2.5V.The negative sign indicates that the emf is opposite to the emf of the cell which is 0.5V.Since the cell is getting charged, the difference in emf is gradually reduced to zero when the cell is fully charged.In modern charging units there are provisions so that the cell is never allowed to be over charged, even if the charging unit is in on for about 12 hours.When the cell is fully charged, (that is when the emf of the cell is now 1.5V), the potential difference between either the second source or cell will be zero.Taking into consideration the sign of the emf and the direction of current through the cell and the sign of the potential difference, the potential difference will be always less than the emf of the cell (which gradually increases while charging).Note that the potential difference is negative if the emf of the cell is taken as positive.Also note that the cell is charged only when its emf is less than its maximum e.m.f
Why is kinetic energy always less than gravitational potential energy?
Kinetic energy is always less than gravitational potential energy because an object's kinetic energy is dependent on its velocity, while its gravitational potential energy is determined by its height above the ground. In most scenarios, the object is higher (has more potential energy) before it falls and accelerates, so the gravitational potential energy it loses is converted to kinetic energy, but it is never greater than its original potential energy.
What does Hyperpolarization results from?
Hyperpolarization results from an increase in the membrane potential of a cell beyond its resting state, typically caused by an influx of negatively charged ions or an efflux of positively charged ions. This makes the cell less likely to generate an action potential.
What is the voltage change at the receptor site of a neuron?
When a neuron is activated, there is a change in the voltage across the cell membrane at the receptor site. This change is known as a postsynaptic potential and can be either depolarizing (making the neuron more likely to fire an action potential) or hyperpolarizing (making the neuron less likely to fire an action potential).
What does depolarize and repolarize mean?
Depolarization refers to the change in electrical charge across a cell membrane, where the inside becomes less negative. Repolarization is the return to the cell's resting membrane potential after depolarization. These processes are essential for transmitting electrical impulses in nerve and muscle cells.
Can the potential difference across a battery be greater than its EMF?
If the emf of a battery is E Volt, the potential difference across a battery is given byV = E -I r where I is the current in the circuit and r is the inetrnal resistance.Hence E and V will be equal only when I = 0.The maximum potential difference across the battery will be equal to E only if I = 0.In gnereral potential difference can be equal or less than the emf.E.m.f can never exceed the potential difference.=====================================A battery charger is a device used to put energy into a secondary cell or (rechargeable) batteryby forcing an electric current through it.Hence to charge a battery another source of emf is needed.The combined emf is now will be (E - E1) where E is the emf of the battey in quesiton and E 1 is the emf of the external source used to charge the battery.Note that E-E1 will be negative in sign.======================================...A battery is charged only when its emf is less than its maximum emf.Suppose that the maximum emf of a cell is 1.5V. The battery should be charged only when its emf is less than 1.5 V say 0.5 V.To charge the cell we use a different source of emf E1 say 3V.The positive of the second source is connected to the negative of the cell so that theCombined emf is now 0.5 - 3 = -2.5V.The negative sign indicates that the emf is opposite to the emf of the cell which is 0.5V.Since the cell is getting charged, the difference in emf is gradually reduced to zero when the cell is fully charged.In modern charging units there are provisions so that the cell is never allowed to be over charged, even if the charging unit is in on for about 12 hours.When the cell is fully charged, (that is when the emf of the cell is now 1.5V), the potential difference between either the second source or cell will be zero.Taking into consideration the sign of the emf and the direction of current through the cell and the sign of the potential difference, the potential difference will be always less than the emf of the cell (which gradually increases while charging).Note that the potential difference is negative if the emf of the cell is taken as positive.Also note that the cell is charged only when its emf is less than its maximum e.m.f
How is the resting potential different from repolarization?
The resting potential is the stable membrane potential of a cell at rest, typically around -70mV. Repolarization refers to the return of the membrane potential to its resting value after depolarization, where the cell becomes more negative again due to potassium channels opening.
What is a reduction in membrane potential called?
A reduction in membrane potential is called hyperpolarization. This occurs when the inside of the cell becomes more negative than the outside, making it less likely for the cell to generate an action potential.
What is the difference between hypoxia and ischemia?
simply, Hypoxia is less oxygen supply to cell tissues, while the Ischemia is less blood supply to cell issues.
Why quenching potential is always less than flashing potential?
because flashing potential is potential at which the neon bulb just start conducting or glowing ....while at quenching potential the bulb stops conducting.
What is a Difference between hyperpolarizing and depolarizing graded potential?
A hyperpolarizing graded potential makes the cell more negative, typically caused by an influx of chloride ions or efflux of potassium ions. In contrast, a depolarizing graded potential makes the cell less negative, often due to an influx of sodium ions or calcium ions. Both types of potentials play a role in generating action potentials in neurons.
Why is potential energy of body is negative?
That is an arbitrary definition. In potential energy, an absolute energy is more or less meaningless; what matters is the difference in energy between two positions. For simplicity of definitions, a point at an infinite distance from a mass is often assigned a potential energy of zero; hence, any nearer point must have LESS potential energy.That is an arbitrary definition. In potential energy, an absolute energy is more or less meaningless; what matters is the difference in energy between two positions. For simplicity of definitions, a point at an infinite distance from a mass is often assigned a potential energy of zero; hence, any nearer point must have LESS potential energy.That is an arbitrary definition. In potential energy, an absolute energy is more or less meaningless; what matters is the difference in energy between two positions. For simplicity of definitions, a point at an infinite distance from a mass is often assigned a potential energy of zero; hence, any nearer point must have LESS potential energy.That is an arbitrary definition. In potential energy, an absolute energy is more or less meaningless; what matters is the difference in energy between two positions. For simplicity of definitions, a point at an infinite distance from a mass is often assigned a potential energy of zero; hence, any nearer point must have LESS potential energy.
Why does increasing the extracellular K cause the membrane potential to change?
Increasing extracellular potassium concentration can depolarize the cell membrane potential because potassium ions are leaking out of the cell less efficiently, leading to an accumulation of positive charge outside the cell. This disrupts the normal balance of ions and can make it easier for the cell to depolarize and generate an action potential.
What is depolorization?
Depolarization is a change in a cell's membrane potential, making it more positive, or less negative. In neurons and some other cells, a large enough depolarization may result in an action potential.
If a resting neuron is stimulated and there is an inward flow of positive charges into the cell the membrane potential will?
If a resting neuron is stimulated and there is an inward flow of positive charges into the cell, the membrane potential will depolarize, meaning the inside of the cell becomes less negative. This can trigger an action potential if the depolarization reaches the threshold level.
If a resting potential becomes more negative what happens to the cell?
When the membrane potential becomes more negative it is being hyperpolarized. Remember the resting membrane potential is already at a negative state (~70mV). So if you are making a comparison of a membrane potential that is hyperpolarized in comparison to a resting membrane potential, the resting membrane potential is said to be more depolarized.When the membrane potential becomes more positive it is called depolarization.
A depolarizing graded potential?
A depolarizing graded potential is a change in membrane potential that makes the inside of the cell less negative. This can occur due to the influx of positively charged ions such as sodium into the cell. Depolarizing graded potentials are involved in generating action potentials in excitable cells.
