Ans. (c)
Ans. (b)
Ans. (b)
Ans. (d)
Ans. (a)
Ans. (d)
Ans. (d)
Ans. (d)
Ans. (d)
Ans. (b)
Ans. (d)
A plug (named infinity plug) is taken out from resistance box so air gap is introduced there. Since air is bad conductor of current. Therefore, no current flows in the circuit which implies resistance of infinity resistance is introduced in the circuit.
Ans. (b)
Ans. (a)
We can take an example, when North Pole of magnet is moved towards a coil, one end of coil [near to magnet] develops north polarity hence repelling the magnet. Now we have to apply external force to move the magnet towards coil. This external work done gets converted into induced emf in coil. So Lenz's law is consequence of conservation of energy.
Ans. (b)
Ans. (a)
Ans. (c)
Ans. (d)
Ans. (c)
Ans. (d)
Ans. (d)
Ans. (d)
Ans. (a)
Case (a); Space varying magnetic field means field at different points are different and constant in magnitude so there will be no change in flux of metal plate hence no induced current will be there in plate so no heat loss/dissipation.
Case (b), (c); Alternating current or direct current will heat up plate due to heat loss.
Case (d); In time varying magnetic field, emf gets induced so induced current heats up the plate.
Ans. (d)
Ans. (a)
Ans. (c)
Ans. (d)
Ans. (a)
Ans. (c)
Ans. (c)
Ans. (a)
Ans. (c)
Ans. (d)
Ans. (a)
Ans. (d)
Ans.(c)
Given, connecting wire is attached at given points, that makes same potential at the end of connection so, circuit can be redrawn as. All capacitors are identical
Ans. (a)
Ans. (c)
Ans. (a)
Ans. (d)
Ans. (d)
Ans. (a)
Ans. (d)
Ans. (d)
Ans. (b)
Ans. (c)
(A): A bar magnet experiences a torque in magnetic field
= MB sin So, assertion is true
(R): A bar magnet exerts torque due to other's magnetic field (not its own magnetic field)
So, reason is not true.
Ans. (b)
(A): When LCR connected to an AC source, LCR circuit shows the resonance at XL XC because not its reason
(R): It is true.
Ans. (a)
(A): A positive charged particle enters in magnetic field normally. It makes the circular path.
Ans. (a)
Ans. (a)
(A): A transformer is used to increase or decrease AC voltage only (not dc) because AC voltage provides changing in current which produce magnetic flux.
(R): Transformer works on the principle of mutual induction between primary coil and secondary coil.
Both A and R are true but R is not the correct explanation of A.
This section consists of 6 multiple choice questions with an overall choice to attempt any 5 questions. In case more than the desirable number of questions are attempted, only the first 5 questions will be considered for valuation.
Ans. (b)
When two charged spheres are connected together, charge flows from one sphere to other in such a way that potentials of both spheres become equal.
Ans. (d)
Ans. (c)
Ans. (b)
Ans. (a)
Ans. (c)