List of top Physics Questions

As shown in the figures, a uniform rod $ OO' $ of length $ l $ is hinged at the point $ O $ and held in place vertically between two walls using two massless springs of the same spring constant. The springs are connected at the midpoint and at the top-end $ (O') $ of the rod, as shown in Fig. 1, and the rod is made to oscillate by a small angular displacement. The frequency of oscillation of the rod is $ f_1 $. On the other hand, if both the springs are connected at the midpoint of the rod, as shown in Fig. 2, and the rod is made to oscillate by a small angular displacement, then the frequency of oscillation is $ f_2 $. Ignoring gravity and assuming motion only in the plane of the diagram, the value of $\frac{f_1}{f_2}$ is:

In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by:

With the help of the given circuit, find out the total resistance of the circuit and the current flowing through the cell.

 

The output of the circuit is low (zero) for:

(A) \( X = 0, Y = 0 \) 
(B) \( X = 0, Y = 1 \) 
(C) \( X = 1, Y = 0 \) 
(D) \( X = 1, Y = 1 \)
Choose the correct answer from the options given below:

The alternating current \( I \) in an inductor is observed to vary with time \( t \) as shown in the graph for a cycle.
 

Which one of the following graphs is the correct representation of wave form of voltage \( V \) with time \( t \)?}