For accurate measurements, the resistance of a voltmeter should be
Use figure given below for questions 2 to 4
- as small as possible
- as large a possible
- equal to the resistance across which potential difference is to be measured
Consider the circuit given below
The rate at which energy is dissipated is 20Ω resistor
(a) 14.2 Watt
(b) 8.97 Watt
(c) 97.7 Watt
(d) 47.2 Watt
Current through 10Ω resistor is
- 1.54 A
- 0.67 A
- 1.22 A
- 2.21 A
Power of battery having emf E1
Solution 2, 3, 4
- 44.2 Watt
- 30.8 Watt
- 13.4 Watt
- 20 Watt
Consider the figure given below
If ammeter shows a reading of 10A and voltmeter having internal resistance 3000 Ω measures a voltage of 200V, the resistance R is given by
- 201.3 Ω
- 2013 Ω
- 20.13 Ω
- 20.00 Ω
A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if
(a) both length and radius of wire are halved
(b) both length and radius of wire are doubled
(c) the radius of wire id doubled
(d) length of wire is doubled
If a wire of resistance 2Ω is covered with ice and a voltage of 210V is applied across the wire , then rate of melting ice would be
- none of the above
Which of the following statements is/are correct?
- Both Peltier and Joule effects are reversible
- Both Peltier and Joule effects are irreversible
- Joule effect is reversible and Peltier effect is irreversible
- Joule effect is irreversible and Peltier effect is reversible
The arrangement shown below is of the meter bridge experiment. Here AC=x corresponds to the null deflection in the galvanometer. What will be the value of AC if the radius of the wire AB is doubled?
Assertion Reason type questions
- Both assertion and reason are true and reason is correct explanation of assertion
- Both assertion and reason are true and reason is not the correct explanation of assertion
- Assertion is true but reason is false
- Both assertion and reason are false.
The distribution of currents within the network for a given amount of current always takes place in a way that leads to minimum total power distribution in the circuit
For maximum output current by a source the source resistance must be equal to external load resistance.
When temperature of a cold junction of a thermocouple is lowered , the value of neutral temperature of this thermocouple rises
More thermo emf is produced when temperature difference between two junctions of thermocouple is raised.
A domestic appliance, working on a three pin , will continue working even if the top pin is removed
Third pin is used as a safety device.
A potentiometer of larger length is used for accurate measurements
Potential gradient for potentiometer of larger length with a given battery becomes small.
Class 12 Maths
Class 12 Physics