Which of the following statement is not correct ?
i) If the resistors are connected in series, the current is the same in every part of the circuit.
ii) Series combination is used to increase resistance in a circuit.
iii) If the resistors are connected in parallel, the effective resistance of the combination is more than the individual resistance in the combination.
iv) In parallel combination, the voltage across each resistor is different.
(i) &(ii)
(ii) & (iv)
(ii) & (iii)
(iii) & (iv)
Why are copper wires used as connecting wires ?
copper is available in abundance
copper conducts electricity and heats up appliances.
Electrical resistivity of copper is low.
Copper is cheap.
Current is expressed in
Volt
Ohm
Ampere
Coulomb
How many bulbs of 10 Ω should be joined in parallel to draw a current of 4 A from a battery of 8 V ?
3
4
5
6
If potential difference across the ends of a conductor is V and the current flowing through it is I, then the voltage is given by
I2 R
IR
Find the amount of work done if 2C of charge is moved through a potential difference of 9 V.
16J
17J
18J
19J
What is the S.I unit of charge?
What will be the ratio of the effective resistance of 3 resistances, if they are connected in series and then in parallel ?
R
R2
9
1
Which of the following diagram represents a variable resistance ?
Three resistance 20 Ω, 25 Ω and 30 Ω are connected in parallel, find the effective resistance of the circuit?
8.108
9.109
7.107
6.106
