grishma gautam

Non-ohmic resistors are resistors that do not obey Ohm's law, meaning their resistance does not depend linearly on the applied voltage. Examples include thermistors, photoresistors, tunnel diodes, and field-effect transistors. A galvanometer is a device used to measure electric current. It can be converted into an ammeter by connecting a low resistance in series with the galvanometer. This resistance should be low enough that it does not significantly affect the current being measured, but...

Kirchhoff’s current and voltage laws depend on conservation of energy. Both of Kirchhoff's laws can be understood as corollaries of the Maxwell equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits.

When we use voltmeter in an electrical circuit it draws current from the circuit so it measures only the potential difference across the circuit but not the emf of cell. But if we use potentiometer, at null point no current is drawn from the cell. Also, the potential measured by the voltmeter is always less than emf.

A Carnot engine whose high-temperature reservoir is at 620 K takes in 550 J of heat at this temperature in each cycle and gives up 335 J to the low-temperature reservoir. (a) How much mechanical work does the engine perform during each cycle? (b) What is

Solution:

Given,

Temperature of high-temperature reservoir (T1) = 620 K

Energy taken in each cycle (Q1) = 550 J

Energy given to low-temperature reservoir (Q2) = 335J

Now,

Mechanical work done in each cycle = Q1 - Q2

= 550 J - 335 J

= 215 J

Let the...

Answer: Heat pumps are designed to move thermal energy opposite to the direction of spontaneous heat flow by absorbing heat from a cold space and releasing it to a warmer one.Due to surrounding temperaturea refrigerator consume more power in summer than in winter to cool the same quantity of food by same degree.

1.ans: No the tension in the string of a simple pendulum is not constant throughout the motion

2.ans: If the amplitude of the simple harmonic oscillator is doubled then: ...