Electromagnetic Induction — Physics STD 12 Science — Question

The mass number of a nucleus is(a) Always less than its atomic number(b) Always more than its atomic number (c) Always equal to its atomic number (d) Sometimes more than and sometimes equal to its atomic number

If heat is supplied to an ideal gas in an isothermal process:

1. The internal energy of the gas will increase.
2. The gas will do positive work.
3. The gas will do negative work.
4. The said process is not possible.

A capacitor with air as the dielectric is charged to a potential of  100 volts. If the space between the plates is now filled with a dielectric of dielectric constant 10, the potential difference between the plates will be(a) 1000  volts (b) 100 volts (c) 10 volts(d) Zero

A 100% efficient transformer has 100 turns in the primary and 25 turns in its secondary coil. If the current in the secondary coil is 4 amp, then the current in the primary coil is(a) 1 amp (b) 4 amp(c) 8 amp (d) 16 amp

A square loop of side l is moving with a constant velocity v in a uniform magnetic field. The magnitude of induced emf is:

Two positive point charges of 12 μC  and 8 μC  are 10cm apart. The work done in bringing them 4 cm closer is (a) 5.8 J   (b) 5.8 eV(c) 13 J(d) 13 eV

Two metal plates having charges Q, -Q face each other at some separation and are dipped into an oil tank. If the oil is pumped out, the electric field between the plates will:

1. Increase.
2. Decrease.
3. Remain the same.
4. Become zero.

Choose the correct option about light.