Physics Test - ...

In the given circuit the average power developed is -

Two balls with equal charges are in a vessel with ice at −10 °C at a distance of 25 cm from each other. On forming water at 0 °C, the balls are brought nearer to 5 cm for the interaction between them to be same. If the dielectric constant of water at 0 °C is 80, the dielectric constant of ice at −10 °C is

The current gain of a common emitter amplifier is 69. If the emitter current is 7.0 mA, collector current is :

Two electric lamps A and B radiate the same power. Their filaments have the same dimensions and have emissivities e_A and e_B respectively. Their surface temperatures are T_A and T_B. The ratio T_A/T_B will be equal to

A car is moving with 90 km/h blows a horn of 150 Hz, towards a cliff. The frequency of the reflected sound heard by the driver will be (speed of sound in air is 340 m/s)

In the figure shown if the object 'O' moves towards the plane mirror, then the image I (which is formed after successive reflections from M₁ & M₂ respectively) will move:

Which of the following statements is false?

When photons of wavelength λ₁ are incident on an isolated sphere, the corresponding stopping potential is found to be V. When photons of wavelength λ₂ are used, the corresponding stopping potential was thrice that of the above value. If light of wavelength λ₃ is used then find the stopping potential for this case:

Two blocks of masses 10 kg and 4 kg are connected by a spring of negligible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 14 ms⁻¹to the heavier block in the direction of the lighter block. The velocity of the centre of mass is

A concave mirror is placed on a horizontal table, with its axis directed vertically upwards. Let O be the pole of the mirror and C its centre of curvature. A point object is placed at C. It has a real image, also located at C (a condition called auto-collimation). If the mirror is now filled with water, the image will be: