Hi CUET aspirants, Welcome to Amans Maths Blogs (AMBIPi). In this post, you will get CUET Physics Current Electricity Revision Notes AMBIPi. This CUET Physics Notes are designed by analyzing to the CUET Syllabus and CUET Previous Years Questions Papers.
CUET Physics Notes
CUET Physics Current Electricity: Important Points to Remember
There are following important points in this chapter of Current Electricity.
- A conducting device obeys ohm’s law when the resistance of device is independent of the magnitude and the polarity of the applied potential difference.
- Ohm-metre is the unit of resistivity where as ohm meter is an instrument to measure the resistance.
- Ohm’s law fails when V/I is not constant.
- In a circuit current can be kept continuous by maintaining a constant, potential difference between the two points.
- Relaxation time decreases with rise in temperature.
- The meterbridge cannot be used to measure very high or very low resistances.
- Balanced position of meterbridge is not affected on interchanging the position of battery and galvanometer.
- Potentiometer is based on null deflection method.
- Voltmeter is based on deflection method.
- Kirchoff’s law are equally applicable to a.c as well as d.c circuit.
- The commercial unit of electric energy is called kilowatthour (KWh) or Board of Trade unit (B.O.T.U) or unit of
electricity. - Joule’s heating effect of current is common to both a.c & d.c. That is why the instrument or electrical appliances such as heater, iron, geyser, toaster etc. work both on a.c and d.c.
- In series combination, potential difference and power consumption will be more in higher resistance as P = I2R, V = IR.
- In parallel combination, the current & power consumed will be more in small resistance. P = V2/R, I = V/R.
- The cells are connected in series to get more voltage, in parallel to get more current, and in mixed grouping to get
more power. - In parallel grouping if one bulb get fused, other bulb will work.
- In series grouping, if one bulb get fused other bulb will not work.
- A fuse wire is one which has high resistance and low melting point.
- E.M.F of cell represents work per unit charge.
- Resistance of a conductor increases with decrease in density or when it is subjected to mechanical stress.
- Using n conductors of equal resistances, the maximum number of combination one can have, using all at a time is
2n–1. - Using n conductors of different resistances, the number of possible combinations are 2n.
- If the radius of the metallic wire becomes n times by stretching, the resistance becomes 1/n4 times.
- In parallel combination of electric bulb, the resistance of 100W bulb is less than that of 50W bulb.
- In series combination of electric bulb, the brightness of 50W bulb is more than that of 100W bulb.
- When the bulb of different wattage but of same rated voltages are connected in series and if the voltage supplied
is twice the rated voltage then the bulb with the least wattage fuse off. - Current is a scaler quantity.
- J = σE microscopic form of ohm’s law
CUET Physics Current Electricity: Important Graphs
1. Series Grouping :
2. Parallel Grouping
3. Mixed Combination
4. Wheat Stone Bridge
When current through the galvanometer is zero (null point or balance point) P / Q = R / S.
When PS > QR, VC < VD & PS < QR, VC > VD. or PS = QR ⇒ products of opposite arms are equal.
5. Metre Bridge
CUET Physics Current Electricity: Important Formulas
1. Current, Electric Conduction Ohm’s law, Resistance
2. Heating Effect of Current & Chemical Effect of Current
3. Different Measuring Instruments
4. Grouping of Resistances, Kirchoff’s Law, Internal Resistance, Potential Difference
CUET Physics Mock Test
Now, you have revised the this CUET Physics chapter. So, you must need to practice CUET Physics Sample Papers. By solving these CUET Physics questions, you will be more confident about your CUET preparations.