Advertisements
Advertisements
Question
The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become ______.
Options
four times
two times
half
one forth
Advertisements
Solution
The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become two times.
Explanation:
Joule’s Law of Heating:
`H = I^2Rt = V^2/R t`
If voltage V is constant, use: `H = V^2/Rt`
If current III is constant, use: H=I2Rt
`H = V^2/R t`
If R is reduced to `R/2`
`H_"new" = V^2/(R/2) t = V^2/R . 2t = 2 . H_"origional"`
2 . two times
APPEARS IN
RELATED QUESTIONS
Find the resistance of a conductor if 0.24 A current is passing through it and a potential difference of 24 V is applied across it.
Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
Fill in the following blank with suitable words:
Resistance is measured in .............. The resistance of a wire increases as the length ..............; as the temperature ..............; and as the cross-sectional area .............. .
Calculate the current flowing through a wire of resistance 5 Ω connected to a battery of potential difference 3 V.
Consider the sacle of voltmeter shown in the diagram and answer the following questions :
(a) What is the least count of the voltmeter?
(b) What is the reading shown by the voltmeter ?
(c) If the voltmeter is connected across a resistor of 20 `Omega` how much current is flowing through the resistor?
Tick(✓) the correct choice in the following:
Ohm's law is applicable to
State and define Ohm’s law.
Which of the following is correct for V-I graph of a good conductor?
A current of 0.8 A flows in a conductor of 40 Ω for 1 minute. The heat produced in the conductor will be ______.
