MCQOPTIONS
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MCQOPTIONS
This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If a glass tube is of insufficient length, water rises and overflows. |
| A. | True |
| B. | False |
| Answer» C. | |
| 2. |
Consider a capillary tube in which water has risen. The contact angle is θ. The radius of the capillary tube is ‘r’. The surface tension is ‘S’. And the density of water is ‘ρ’. What is the expression for the height of water risen in the tube? Assume the radius of meniscus to be ‘R’. Let the height of water risen in the tube be ‘h’. |
| A. | 2Ssinθ / Rρg |
| B. | 2S / Rρg |
| C. | 2Scosθ / Rρg |
| D. | 2S / rρg |
| Answer» C. 2Scosθ / Rρg | |
| 3. |
The contact angle determines whether liquid will rise or get depressed along a solid surface. Select the correct statement regarding the same. |
| A. | If contact angle is found to be less than 90°, the liquid will have raise along the solid surface |
| B. | If contact angle is found to be greater than 90°, then liquid will have depressed along the solid surface |
| C. | Liquid always rises along solid surface, irrespective of contact angle |
| D. | Liquid always gets depressed along solid surface, irrespective of contact angle |
| Answer» B. If contact angle is found to be greater than 90°, then liquid will have depressed along the solid surface | |
| 4. |
A soap bubble contains two surface layers. What is the excess pressure just inside the first layer when seen from outside the bubble? |
| A. | 2S/R |
| B. | 4S/R |
| C. | -2S/R |
| D. | -4S/R |
| Answer» B. 4S/R | |
| 5. |
What is the value of pressure inside the bubble of radius 1cm, if the bubble is in water at a depth (H) of 1m? Assume atmospheric pressure to be 1atm, surface tension = 0.075N/m & density of water = 1000kg/m3. |
| A. | 110015 Pa |
| B. | 109985 Pa |
| C. | 26 atm |
| D. | 4 atm |
| Answer» B. 109985 Pa | |
| 6. |
Consider a spherical drop of liquid having radius ‘R’. Assume a diametric cross-section which divides the drop into two hemispheres. The hemispheres pull each other due to surface tension along the circumference of the diametrical cross-section. What is the value of this force? |
| A. | 2πRS |
| B. | πR2 S |
| C. | 2RS |
| D. | 0 |
| Answer» B. πR2 S | |
| 7. |
What will be the change in surface energy when a drop of liquid (S = 0.08N/m) is divided into 10 equal droplets? Radius of initial single drop (R)= 5cm. |
| A. | 0.1259 J |
| B. | 0.1141 J |
| C. | 0.2356 J |
| D. | 0.1765 J |
| Answer» C. 0.2356 J | |
| 8. |
A U-shaped frame consists of a sliding rod connecting its two arms. It is dipped in a soap solution and then placed horizontally. The weight of the sliding rod is 100gm. Surface tension (S) = 0.05 & length of sliding wire = 20cm. If the sliding rod starts from rest at t=0, find its velocity at t=5s. Assume that there are no resistive forces. |
| A. | 0.5 m/s |
| B. | 3.6 km/hr |
| C. | 1 km/hr |
| D. | 2 m/s |
| Answer» C. 1 km/hr | |
| 9. |
The unit of surface tension is same as that of _________ |
| A. | surface energy per unit volume |
| B. | force per unit area |
| C. | surface energy per unit area |
| D. | surface energy per unit length |
| Answer» D. surface energy per unit length | |
| 10. |
Consider two lines on the surface of water kept in a beaker. The length of one line is twice the others. A force will be acting on the lines from either side. What is the ratio of magnitude of F1 & F2? |
| A. | 2:1 |
| B. | 1:1 |
| C. | 1:2 |
| D. | 2:3 |
| Answer» B. 1:1 | |
| 11. |
Surface energy is ________________ |
| A. | kinetic energy of the surface molecules |
| B. | the force per unit length acting on surface particles |
| C. | the energy of the molecules inside the beaker |
| D. | the extra energy that the molecules at the surface have relative to molecules inside the liquid |
| Answer» E. | |