PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Physics

Derive the expression for force per unit length between two long straight parallel current carrying conductors. Hence define one ampere.

If a positive charge is shifted from a low-potential region to a high-potential region, the electric potential energy ______.

Two equal positive charges are kept at points A and B. The electric potential at the points between A and B (excluding these points) is situated while moving from A to B. The potential  

The thermal energy developed in a current-carrying resistor is given by U = i² Rt and also by U = Vit. Should we say that U is proportional to i² or i?

Consider a circuit containing an ideal battery connected to a resistor. Do "work done by the battery" and "the thermal energy developed" represent two names of the same physical quantity?

Is work done by a battery always equal to the thermal energy developed in electrical circuit? What happens if a capacitor is connected in the circuit?

A non-ideal battery is connected to a resistor. Is work done by the battery equal to the thermal energy developed in the resistor? Will your answer change if the battery is ideal?

Sometimes it is said that "heat is developed" in a resistance when there is an electric current in it. Recall that heat is defined as the energy being transferred due to temperature difference. Is the statement in quotes technically correct?

As the temperature of a metallic resistor is increased, the product of its resistivity and conductivity ____________ .

Two resistors R and 2R are connected in series in an electric circuit. The thermal energy developed in R and 2R are in the ratio ______________ .

The resistance of an iron wire and a copper wire at 20°C are 3.9 Ω and 4.1 Ω, respectively. At what temperature will the resistance be equal? Temperature coefficient of resistivity for iron is 5.0 × 10^–3 K^–1 and for copper, it  is 4.0 × 10^–3 K^–1. Neglect any thermal expansion.

When a current passes through a resistor, its temperature increases. Is it an adiabatic process?

Is inversion temperature always double the neutral temperature? Does the unit of temperature have an effect in deciding this question?

Is neutral temperature always the arithmetic mean of the inversion temperature and the temperature of the cold junction? Does the unit of temperature have an effect in deciding this question?

As temperature increases, the viscosity of liquids decreases considerably. Will this decrease the resistance of an electrolyte as the temperature increases?

A charged particle goes undeflected in a region containing an electric and a magnetic field. It is possible that
(a) `vecE" || "vecB , vecv" || " vec E `
(b) `vecE  "is not parallel"  vecB`
(c) `vecv " || " vecB  but  vecv  "is not parallel"`
(d) `vecE" || " vecB  but   vecv "is not parallel"`

 and ```vecE` and  `vecB`denote electric and magnetic fields in a frame S and `vecE`→ and `vecB` in another frame S' moving with respect to S at a velocity `vecV` Two of the following equations are wrong. Identify them.
(a) `B_y^, =  B_y + (vE_z)/c^2`

(b) `E_y^' = E_y - (vB_z)/(c^2)`

`(c) Ey = By + vE_z`

`(d) E_y = E_y + vB_z`