CBSE 12 Physics Question Paper-2021 Term-1

Which of the following is NOT the property of equipotential surface?

Two point charges +8q and -2q are located at x=0 and x=L respectively. The point on x axis at which net electric field is zero due to these charges is-

An electric dipole of moment p is placed parallel to the uniform electric field. The amount of work done in rotating the dipole by 90° is-

Three capacitors 2µF, 3µF, and 6µF are joined in series with each other. The equivalent capacitance is-

Two point charges placed in a medium of dielectric constant 5 are at a distance r between them, experience an electrostatic force ‘F’. The electrostatic force between them in vacuum at the same distance r will be-

Which statement is true for Gauss law-

A capacitor plates are charged by a battery with ‘V’ volts. After charging, the battery is disconnected, and a dielectric slab with dielectric constant ‘K’ is inserted between its plates. The potential across the plates of a capacitor will become

The best instrument for accurate measurement of EMF of a cell is-

An electric current is passed through a circuit containing two wires of same material, connected in parallel. If the lengths and radii of the wires are in the ratio of 3:2 and 2:3, then the ratio of the current passing through the wire will be

By increasing the temperature, the specific resistance of a conductor and a semiconductor-

We use alloys for making standard resistors because they have

A constant voltage is applied between the two ends of a uniform metallic wire, heat ‘H’ is developed in it. If another wire of the same material, double the radius and twice the length as compared to the original wire is used, then the heat developed in it will be-

Which of the following is NOT the property of equipotential surface?

Two point charges +8q and -2q are located at x=0 and x=L respectively. The point on x axis at which net electric field is zero due to these charges is-

An electric dipole of moment p is placed parallel to the uniform electric field. The amount of work done in rotating the dipole by 90° is-

Three capacitors 2µF, 3µF, and 6µF are joined in series with each other. The equivalent capacitance is-

Two point charges placed in a medium of dielectric constant 5 are at a distance r between them, experience an electrostatic force ‘F’. The electrostatic force between them in vacuum at the same distance r will be-

Which statement is true for Gauss law-

A capacitor plates are charged by a battery with ‘V’ volts. After charging, the battery is disconnected, and a dielectric slab with dielectric constant ‘K’ is inserted between its plates. The potential across the plates of a capacitor will become

The best instrument for accurate measurement of EMF of a cell is-

An electric current is passed through a circuit containing two wires of same material, connected in parallel. If the lengths and radii of the wires are in the ratio of 3:2 and 2:3, then the ratio of the current passing through the wire will be

By increasing the temperature, the specific resistance of a conductor and a semiconductor-

We use alloys for making standard resistors because they have

A constant voltage is applied between the two ends of a uniform metallic wire, heat ‘H’ is developed in it. If another wire of the same material, double the radius and twice the length as compared to the original wire is used, then the heat developed in it will be-

A straight line plot showing the terminal potential difference (V) of a cell as a function of current (I) drawn from it, is shown in the figure. The internal resistance of the cell would be then

A 10 m long wire of uniform cross-section and 20 Ω resistance is used in a potentiometer. The wire is connected in series with a battery of 5 V along with an external resistance of 480 Ω. If an unknown emf E is balanced at 6.0 m length of the wire, then the value of unknown emf is-

The current sensitivity of a galvanometer increases by 20%. If its resistance also increases by 25%, the voltage sensitivity will

Three infinitely long parallel straight current carrying wires A, B, and C are kept at equal distance from each other. The wire C experiences net force F. The net force on wire C, when the current in wire A is reversed, will be

In a hydrogen atom, the electron moves in an orbit of radius 0.5 Å making 10 revolutions per second. The magnetic moment associated with the orbital motion of the electron will be

An air-cored solenoid with length 30 cm, area of cross-section 25 cm², and number of turns 800, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10^-3 s. Ignoring the variation in magnetic field near the ends of the solenoid, the average back emf induced across the ends of the open switch in the circuit would be