Advertisements
Advertisements
प्रश्न
Keeping the p.d. constant, the resistance of a circuit is halved. The current will become:
(a) one-fourth
(b) four time
(c) half
(d) double
Advertisements
उत्तर
d) double
As we know from Ohm’s law:
Voltage = Current x Resistance
V = IR
If the voltage is constant, the resistance of the circuit is halved. That is, it becomes R / 2.
Current, I = V/R
I = V/R
I = V/R/2 = 2 I
Thus by keeping the p.d. constant, the resistance of a circuit is halved and the current is doubled.
APPEARS IN
संबंधित प्रश्न
What is an Ohmic resistor?
What is the necessary condition for a conductor to obey Ohm’s law?
Calculate the current flowing through a wire of resistance 5 Ω connected to a battery of potential difference 3 V.
Define the following:
Coulomb
What is meant by the drift speed of free electrons?
State the relation correlating the electric current flowing in a conductor and the voltage applied across it. Also, draw a graph to show this relationship.
What is non-ohmic resistor?
An ammeter placed in series with an electric radiator reads 0.5 amps and a voltmeter placed across it reads 230 volts. What is the resistance of the radiator?
Choose the correct alternative.
Which of the following is an ohmic conductor?
What is ohmic device?
What is non ohmic device?
Explain the equivalent resistance of a series resistor network.
Explain the equivalent resistance of a parallel resistor network.
The resistance of a nichrome wire at 0°C is 10Ω. If its temperature coefficient of resistivity of nichrome is 0.004/ °C, find its resistance of the wire at boiling point of water. Comment on the result.
An electronics hobbyist is building a radio which requires 150 Ω in her circuit, but she has only 220 Ω, 79 Ω, and 92 Ω resistors available. How can she connect the available resistors to get the desired value of resistance?
Two cells each of 5V are connected in series across an 8Ω resistor and three parallel resistors of 4Ω, 6Ω, and 12Ω. Draw a circuit diagram for the above arrangement. Calculate
- the current drawn from the cell
- current through each resistor
A heater of 220 V heats a volume of water m 5 mint time. A heater of 110 V heat in ten second. The resistance of the conductor is
A current of 2amp flowing through a conductor produced 80 joule of heat in 10 sec. The resistance of the conductor is:-
Why should an ammeter have low resistance?
