JEE Main Physics MCQs - Part 9

Questions 81-90 of 100

81. A simple pendulum is suspended from the ceiling of an elevator. If the elevator accelerates upwards with acceleration a, the new time period T' in terms of original period T is:

82. The escape velocity from Earth's surface is v_e. The escape velocity from a point at a height R (radius of Earth) above the surface is:

83. The ratio of escape velocity to orbital velocity (very close to Earth's surface) is:

84. The magnetic field inside an infinitely long solenoid carrying current I with n turns per unit length is:

85. A magnetic dipole of moment M is placed in a uniform magnetic field B at an angle θ. The torque acting on it is:

86. The magnetic susceptibility χ of a diamagnetic substance is:

87. The displacement current flows in the region where the:

88. The power factor of an LCR series circuit at resonance is:

89. The Q-factor of a resonant LCR circuit is given by:

90. Two rods of the same length and material but different radii r₁ and r₂ are subjected to the same temperature difference. The ratio of their rates of heat flow is: