Multiple Choice QuestionsIn an AC circuit the potential differences across an inductance and resistance joined in series are respectively 16 V and 20 V. The total potential difference of the source is
20.0 V
25.6 V
31.9 V
53.5 V
The focal length of the objective and eye lenses of a microscope are 1.6 cm and 2.5 cm respectively. The distance between the two lenses is 21. 7 cm. If the final image is formed at infinity. What is the linear magnification?
11
110
1.1
44
Assertion: : A current continues to follow in superconducting coil even after switch is off.
Reason: Superconducting coils show Meissner effect.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: Dipole oscillations produce electromagnetic waves.
Reason: Accelerated charge produces electromagnetic waves.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Asserion: : NAND is a universal gate.
Reason: It can be used to describe all other logic gates.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: In a cavity within a conductor, the electric field is zero.
Reason: Charges in a conductor reside only at its surface.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: Ferro magnetic substances become paramagnetic above Curie temperature.
Reason: Domains are destroyed at high temperature.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
A.
If both assertion and reason are true and reason is the correct explanation of assertion
Voltmeter must be connected in parallel to the device because no current flowing through it due to very high resistance. Voltage drop will occur. So we get voltage. Now if it is connected in series then due to high resistance no current will flow through circuit. So no voltage drop occur. Voltage in same line is zero. It indicates zero.
A voltmeter measures the voltage difference between two different points ( say on different sides of resistor), but it should not change the amount of current going through the element between those two points. So, it should be very high resistance.
A voltmeter is always connected in parallel. This has of course a large resistance.
Assertion: Ohm's law is applicable for all conducting elements.
Reason: Ohm's law is a fundamental law.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
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