HARD
12th ICSE
IMPORTANT
Earn 100

A 60 W bulb is switched on in a room. A 240 W heater is also turned on in the same room. The voltage of the mains is 120 V and the resistance of the connecting leads is 6 Ω. What is the change in the voltage at the bulb when the heater is turned on?

Important Questions on Electric Resistance and Ohm's Law

EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 42

How can three resistances of 2 Ω, 3 Ω and 6Ω be connected to give an equivalent resistance of 4 Ω?

EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 43
Join three 3 Ω resistances to obtain an effective resistance of 2 Ω.
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 44
A 5 Ω resistor is connected in series with a parallel combination of n resistors each of 6 Ω. The equivalent resistance is 7 Ω Find n.   
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 45
Three resistors 2 Ω, 4 Ω and 5 Ω are joined in parallel and connected to a battery of 20 V and negligible internal resistance. Find current drawn from the battery.
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 45
Three resistors 2 Ω, 4 Ω and 5 Ω are joined in parallel and connected to a battery of 20 V and negligible internal resistance. Find current through each resistor.
MEDIUM
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 46
A 150 Ω electric heater can take a maximum current of 1.1 A. What minimum resistance should be joined in series with it so that it may be operated at 220 V mains?   
MEDIUM
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 47
An arc lamp operated at 80 V takes 10 A current. How much resistance should be connected in series with the lamp to use it at 240 V mains so that it takes the same current?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 48
A filament lamp of 200 Ω resistance is used at 150 V supply. How much resistance should be joined in series with it to use it at 210 V supply?