Physics

The value of alternating emf (E) in the given circuit will be

Two conducting rods inclined at  $\text{'}\theta \text{'}$ angle from horizontal are kept parallel at separation $\text{'}l\text{'}$ to each other. A resistor of resistance $R$ joins the two rods at their topmost point. A metal bar of length $\text{'}l\text{'}$ is free to slide on the rods as shown in figure. on releasing from rest, the maximum speed that can be attained by the bar if a constant magnetic field $B$ exists vertically downwards, is

A farsighted person cannot focus distinctly objects closer than 100cm. The lens that will permit him to read from a distance of 50cm, will have a focal length:

Figure shown four plates each of area A and separated from another by a distance d. What is the capacitance between P and Q?

If $$ $a\cdot b=\left|a*b\right|$ , then the $\theta$ angle $$ between a and b will be

Consider the following two statements .

(A)The gravitational force on a particle inside a spherical shell is zero.

(B) Total mechanical energy of a body on earth's surface may be positive.

Which of the following options is correct?

A body possesses kinetic energy x, moving on a rough horizontal surface, is stopped in a distance y. The friction force exerted on the body is

A man who can swim with a speed of  $2kh/h$ wants to cross a river $200m$ wide. If the river is flowing with a speed of $3km/h$  then in what minimum time can the man cross the river?

Two rods with lengths 20.123 cm and 18.1 cm are placed side by side. The difference in their lengths is