Q4.A uniform force of (2iˆ+ ˆj) N acts on a particle of mass 1 kg. The particle displaces from position (3 ˆj + ˆk ) m to (5iˆ+ 3ˆj) m. The work done by the force on the particle is
Answer : Option CExplaination / Solution: No Explaination.
Answer : Option DExplaination / Solution:
force is required to start a stationary object and to stop a moving object due to inertia. Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. This is also called law of inertia or newton's first law of motion
Answer : Option BExplaination / Solution:
The standard voltage and frequency of alternating current supply in India is set to 220 V and 50Hz respectively by the government of India because
when power has to be transmitted from a power plant, the biggest challenge is to cut the transmission losses. For this purpose, the current value should be small and potential difference(Voltage) should be more. Also losses are minimal at 50 Hz/60 Hz frequency.
Q9.Electric potential energy of two point charges q and q0 is
Answer : Option BExplaination / Solution: Potential energy of a system of charges is the work done in assembling the charges. Force between two charges q and q0 placed at a distance r apart is F=q0q4πε0r2Potential energy of the charges is given by℧=∫∞r−F∙dr=∫∞r−q0q4πε0r2dr=qq04πε0r