| List I (electronic device) | List-II(Use/application) | ||
|---|---|---|---|
| A | Photodiode | I | Remote controls |
| B | Zener diode | II. | Amplifier |
| C | Light emitting diode | III | Voltage regulator |
| D | Transistor | IV | Photodetector |
The magnitude of heat exchanged by a system for the given cyclic process ABC (as shown in the figure) is (in SI units):

As shown below, bob A of a pendulum having massless string of length \( R \) is released from \( 60^\circ \) to the vertical. It hits another bob B of half the mass that is at rest on a frictionless table in the center. Assuming elastic collision, the magnitude of the velocity of bob A after the collision will be (take \( g \) as acceleration due to gravity):


A particle of mass \( m \) and charge \( q \) is fastened to one end \( A \) of a massless string having equilibrium length \( l \), whose other end is fixed at point \( O \). The whole system is placed on a frictionless horizontal plane and is initially at rest. If a uniform electric field is switched on along the direction as shown in the figure, then the speed of the particle when it crosses the x-axis is:
Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. that maintaining a positive attitude
Q. even in difficult situations
R. is essential for success
S. and helps overcome obstacles effectively