NCERT Class 11 Physics Gk Questions & Answers
11 Which of the following is wrong? Resistivity of a conductor is
Answer: independent of temperature.
12 What does Newton’s third law states for the conservative forces?
Answer: For every reaction, there is an opposite reaction
13 The conservative frictional force always acts ____________ to the surface of the application of the friction.
14 Two cells of emf’s approximately 5 V and 10 V are to be accurately compared using a potentiometer of length 400 cm.
Answer: The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V.
15 A resistance R is to be measured using a meter bridge. Student chooses the standard resistance S to be 100 Ω He finds the null point at l1 = 2.9 cm. He is told to attempt to improve the accuracy. Which of the following is a useful way?
Answer: He should change S to 3 Ω and repeat the experiment.
16 A cubical region of space is filled with some uniform electric and magnetic fields. An electron enters the cube across one of its faces with velocity v and a positron enters via opposite face with velocity -v. At this instant,
Answer: the magnetic forces on both the particles cause equal accelerations.
17 A circular coil of radius 4 cm and of 20 turns carries a current of 3 amperes. It is placed in a magnetic field of intensity of 0.5 weber/m². The magnetic dipole moment of the coil is
Answer: 0.3 ampere-m²
19 An electron is projected with uniform velocity along the axis of a current carrying long solenoid. Which of the following is true?
Answer: The electron will continue to move with uniform velocity along the axis of the solenoid
20 A current carrying circular loop of radius R is placed in the x-y plane with centre at the origin. Half of the loop with x > 0 is now bent so that it now lies in the y – z plane.
Answer: The magnitude of magnetic moment now diminishes.