MCQ & Assertion-Reason Practice
Practice MCQs and Assertion-Reason questions for CBSE Class 12 board exams. Select an answer to check — explanations reveal after submission.
A charge q is placed at the centre of a cube. The electric flux through one face of the cube is:
The SI unit of electric dipole moment is:
When a dielectric slab is inserted between the plates of a charged isolated capacitor, the energy stored:
Assertion (A)
The resistance of a metallic conductor increases with rise in temperature.
Reason (R)
With rise in temperature, the number of free electrons in a metallic conductor increases.
A circular loop of radius r carries current I. The magnetic field at the centre of the loop is:
Assertion (A)
Lenz's law is a consequence of the law of conservation of energy.
Reason (R)
The induced current always opposes the cause that produces it.
In an AC circuit containing only capacitance, the current:
Which of the following has the maximum wavelength?
Assertion (A)
A convex mirror is always used as a rear-view mirror in vehicles.
Reason (R)
A convex mirror always forms a virtual, erect, and diminished image.
In Young's double-slit experiment, if the slit separation is doubled, the fringe width becomes: